interview QuesionsMost frequently asked technical questions.

Q. - What do you know about Java?

Ans. - Java is a high-level programming language originally developed by Sun Microsystems and released in 1995. Java runs on a variety of platforms such as Windows Mac OS and the various versions of UNIX.

Q. - What are the supported platforms by Java Programming Language?

Ans. - Java runs on a variety of platforms such as Windows Mac OS and the various versions of UNIX/Linux like HP-Unix Sun Solaris Redhat Linux Ubuntu CentOS etc.

Q. - List any five features of Java?

Ans. - Some features include Object Oriented Platform Independent Robust Interpreted Multi-threaded. N ));

Q. - What is Java Virtual Machine and how it is considered in context of Java's platform independent feature?

Ans. - When Java is compiled it is not compiled into platform specific machine rather into platform independent byte code. This byte code is distributed over the web and interpreted by virtual Machine (JVM) on whichever platform it is being run.

Q. - Why is Java Architectural Neutral?

Ans. - It's compiler generates an architecture-neutral object file format which makes the compiled code to be executable on many processors with the presence of Java runtime system.

Q. - How Java enabled High Performance?

Ans. - Java uses Just-In-Time compiler to enable high performance. Just-In-Time compiler is a program that turns Java bytecode which is a program that contains instructions that must be interpreted into instructions that can be sent directly to the processor.

Q. - Why Java is considered dynamic?

Ans. - It is designed to adapt to an evolving environment. Java programs can carry extensive amount of run-time information that can be used to verify and resolve accesses to objects on run-time.

Q. - List two Java IDE's?

Ans. - Netbeans Eclipse etc.

Q. - List some Java keywords(unlike C C++ keywords)?

Ans. - Some Java keywords are import super finally etc.

Q. - What do you mean by Object?

Ans. - Object is a runtime entity and it's state is stored in fields and behavior is shown via methods. Methods operate on an object's internal state and serve as the primary mechanism for object-to-object communication.

Q. - Define class?

Ans. - A class is a blue print from which individual objects are created. A class can contain fields and methods to describe the behavior of an object.

Q. - What kind of variables a class can consist of?

Ans. - A class consist of Local variable instance variables and class variables.

Q. - What is a Local Variable?

Ans. - Variables defined inside methods constructors or blocks are called local variables. The variable will be declared and initialized within the method and it will be destroyed when the method has completed.

Q. - What is a Instance Variable?

Ans. - Instance variables are variables within a class but outside any method. These variables are instantiated when the class is loaded.

Q. - What is a Class Variable?

Ans. - These are variables declared with in a class outside any method with the static keyword.

Q. - What is Singleton class?

Ans. - Singleton class control object creation limiting the number to one but allowing the flexibility to create more objects if the situation changes.

Q. - What do you mean by Constructor?

Ans. - Constructor gets invoked when a new object is created. Every class has a constructor. If we do not explicitly write a constructor for a class the java compiler builds a default constructor for that class.

Q. - List the three steps for creating an Object for a class?

Ans. - An Object is first declared then instantiated and then it is initialized.

Q. - What is the default value of byte datatype in Java?

Ans. - Default value of byte datatype is 0.

Q. - What is the default value of float and double datatype in Java?

Ans. - Default value of float and double datatype in different as compared to C/C++. For float its 0.0f and for double it's 0.0d

Q. - When a byte datatype is used?

Ans. - This data type is used to save space in large arrays mainly in place of integers since a byte is four times smaller than an int.

Q. - What is a static variable?

Ans. - Class variables also known as static variables are declared with the static keyword in a class but outside a method constructor or a block.

Q. - What do you mean by Access Modifier?

Ans. - Java provides access modifiers to set access levels for classes variables methods and constructors. A member has package or default accessibility when no accessibility modifier is specified.

Q. - What is protected access modifier?

Ans. - Variables methods and constructors which are declared protected in a superclass can be accessed only by the subclasses in other package or any class within the package of the protected members' class.

Q. - What do you mean by synchronized Non Access Modifier?

Ans. - Java provides these modifiers for providing functionalities other than Access Modifiers synchronized used to indicate that a method can be accessed by only one thread at a time.

Q. - According to Java Operator precedence which operator is considered to be with highest precedence?

Ans. - Postfix operators i.e () [] . is at the highest precedence.

Q. - Variables used in a switch statement can be used with which datatypes?

Ans. - Variables used in a switch statement can only be a string enum byte short int or char.

Q. - When parseInt() method can be used?

Ans. - This method is used to get the primitive data type of a certain String.

Q. - Why is String class considered immutable?

Ans. - The String class is immutable so that once it is created a String object cannot be changed. Since String is immutable it can safely be shared between many threads which is considered very important for multithreaded programming.

Q. - Why is StringBuffer called mutable?

Ans. - The String class is considered as immutable so that once it is created a String object cannot be changed. If there is a necessity to make a lot of modifications to Strings of characters then StringBuffer should be used.

Q. - What is the difference between StringBuffer and StringBuilder class?

Ans. - Use StringBuilder whenever possible because it is faster than StringBuffer. But if thread safety is necessary then use StringBuffer objects.

Q. - Which package is used for pattern matching with regular expressions?

Ans. - java.util.regex package is used for this purpose.

Q. - java.util.regex consists of which classes?

Ans. - java.util.regex consists of three classes − Pattern class Matcher class and PatternSyntaxException class.

Q. - What is finalize() method?

Ans. - It is possible to define a method that will be called just before an object's final destruction by the garbage collector. This method is called finalize( ) and it can be used to ensure that an object terminates cleanly.

Q. - What is an Exception?

Ans. - An exception is a problem that arises during the execution of a program. Exceptions are caught by handlers positioned along the thread's method invocation stack.

Q. - What do you mean by Checked Exceptions?

Ans. - It is an exception that is typically a user error or a problem that cannot be foreseen by the programmer. For example if a file is to be opened but the file cannot be found an exception occurs. These exceptions cannot simply be ignored at the time of compilation.

Q. - Explain Runtime Exceptions?

Ans. - It is an exception that occurs that probably could have been avoided by the programmer. As opposed to checked exceptions runtime exceptions are ignored at the time of compilation.

Q. - Which are the two subclasses under Exception class?

Ans. - The Exception class has two main subclasses : IOException class and RuntimeException Class.

Q. - When throws keyword is used?

Ans. - If a method does not handle a checked exception, the method must declare it using the throws keyword. The throws keyword appears at the end of a method's signature.

Q. - When throw keyword is used?

Ans. - An exception can be thrown, either a newly instantiated one or an exception that you just caught, by using throw keyword.

Q. - How finally used under Exception Handling?

Ans. - The finally keyword is used to create a block of code that follows a try block. A finally block of code always executes, whether or not an exception has occurred.

Q. - What things should be kept in mind while creating your own exceptions in Java?

Ans. - While creating your own exception :- - All exceptions must be a child of Throwable. - If you want to write a checked exception that is automatically enforced by the Handle or Declare Rule, you need to extend the Exception class. - You want to write a runtime exception, you need to extend the RuntimeException class.

Q. - Define Inheritance?

Ans. - It is the process where one object acquires the properties of another. With the use of inheritance the information is made manageable in a hierarchical order.

Q. - When super keyword is used?

Ans. - If the method overrides one of its superclass's methods, overridden method can be invoked through the use of the keyword super. It can be also used to refer to a hidden field.

Q. - What is Polymorphism?

Ans. - Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object.

Q. - What is Abstraction?

Ans. - It refers to the ability to make a class abstract in OOP. It helps to reduce the complexity and also improves the maintainability of the system.

Q. - What is Abstract class?

Ans. - These classes cannot be instantiated and are either partially implemented or not at all implemented. This class contains one or more abstract methods which are simply method declarations without a body.

Q. - When Abstract methods are used?

Ans. - If you want a class to contain a particular method but you want the actual implementation of that method to be determined by child classes, you can declare the method in the parent class as abstract.

Q. - What is Encapsulation?

Ans. - It is the technique of making the fields in a class private and providing access to the fields via public methods. If a field is declared private, it cannot be accessed by anyone outside the class, thereby hiding the fields within the class. Therefore encapsulation is also referred to as data hiding.

Q. - What is the primary benefit of Encapsulation?

Ans. - The main benefit of encapsulation is the ability to modify our implemented code without breaking the code of others who use our code. With this Encapsulation gives maintainability, flexibility and extensibility to our code.

Q. - What is an Interface?

Ans. - An interface is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface.

Q. - Give some features of Interface?

Ans. - - Interface cannot be instantiated - An interface does not contain any constructors. - All of the methods in an interface are abstract.

Q. - Define Packages in Java?

Ans. - A Package can be defined as a grouping of related types(classes, interfaces, enumerations and annotations ) providing access protection and name space management.

Q. - Why Packages are used?

Ans. - Packages are used in Java in-order to prevent naming conflicts, to control access, to make searching/locating and usage of classes, interfaces, enumerations and annotations, etc., easier.

Q. - What do you mean by Multithreaded program?

Ans. - A multithreaded program contains two or more parts that can run concurrently. Each part of such a program is called a thread, and each thread defines a separate path of execution.

Q. - What are the two ways in which Thread can be created?

Ans. - Thread can be created by :- - Implementing Runnable interface - Extending the Thread class

Q. - What is an applet?

Ans. - An applet is a Java program that runs in a Web browser. An applet can be a fully functional Java application because it has the entire Java API at its disposal.

Q. - An applet extend which class?

Ans. - An applet extends java.applet.Applet class.,

Q. - Explain garbage collection in Java?

Ans. - It uses garbage collection to free the memory. By cleaning those objects that is no longer reference by any of the program.

Q. - Define immutable object?

Ans. - An immutable object can't be changed once it is created.

Q. - Explain the usage of this() with constructors?

Ans. - It is used with variables or methods and used to call constructor of same class.

Q. - Explain Set Interface?

Ans. - It is a collection of element which cannot contain duplicate elements. The Set interface contains only methods inherited from Collection and adds the restriction that duplicate elements are prohibited.

Q. - Explain TreeSet?

Ans. - It is a Set implemented when we want elements in a sorted order.

Q. - What is Comparable Interface?

Ans. - It is used to sort collections and arrays of objects using the collections.sort() and java.utils. The objects of the class implementing the Comparable interface can be ordered.

Q. - Explain the following line used under Java Program − public static void main (String args[ ])

Ans. - public − it is the access specifier. static − it allows main() to be called without instantiating a particular instance of a class. void − it affirms the compiler that no value is returned by main(). main() − this method is called at the beginning of a Java program. String args[ ] − args parameter is an instance array of class String

Q. - Define JRE i.e. Java Runtime Environment?

Ans. - Java Runtime Environment is an implementation of the Java Virtual Machine which executes Java programs. It provides the minimum requirements for executing a Java application.

Q. - What is JAR file?

Ans. - JAR files is Java Archive files and it aggregates many files into one. It holds Java classes in a library. JAR files are built on ZIP file format and have .jar file extension.

Q. - What is a WAR file?

Ans. - This is Web Archive File and used to store XML, java classes and JavaServer pages. which is used to distribute a collection of JavaServer Pages, Java Servlets, Java classes, XML files, static Web pages etc.

Q. - Define JIT compiler?

Ans. - It improves the runtime performance of computer programs based on bytecode.

Q. - What is the difference between object oriented programming language and object based programming language?

Ans. - Object based programming languages follow all the features of OOPs except Inheritance. JavaScript is an example of object based programming languages.

Q. - What is the purpose of default constructor?

Ans. - The java compiler creates a default constructor only if there is no constructor in the class.

Q. - Can a constructor be made final?

Ans. - No this is not possible.

Q. - What is static block?

Ans. - It is used to initialize the static data member It is executed before main method at the time of classloading.

Q. - Define composition?

Ans. - Holding the reference of the other class within some other class is known as composition.

Q. - What is function overloading?

Ans. - If a class has multiple functions by same name but different parameters it is known as Method Overloading.

Q. - What is function overriding?

Ans. - If a subclass provides a specific implementation of a method that is already provided by its parent class it is known as Method Overriding.

Q. - Difference between Overloading and Overriding?

Ans. - Method overloading increases the readability of the program. Method overriding provides the specific implementation of the method that is already provided by its super class parameter must be different in case of

Q. - What is final class?

Ans. - Final classes are created so the methods implemented by that class cannot be overridden. It can't be inherited.

Q. - What is NullPointerException?

Ans. - A NullPointerException is thrown when calling the instance method of a null object accessing or modifying the field of a null object etc.

Q. - What are the ways in which a thread can enter the waiting state?

Ans. - A thread can enter the waiting state by invoking its sleep() method by blocking on IO by unsuccessfully attempting to acquire an object's lock or by invoking an object's wait() method. It can also enter the waiting state by invoking its (deprecated) suspend() method.

Q. - How does multi-threading take place on a computer with a single CPU?

Ans. - The operating system's task scheduler allocates execution time to multiple tasks. By quickly switching between executing tasks it creates the impression that tasks execute sequentially.

Q. - What invokes a thread's run() method?

Ans. - After a thread is started via its start() method of the Thread class the JVM invokes the thread's run() method when the thread is initially executed.

Q. - Does it matter in what order catch statements for FileNotFoundException and IOException are written?

Ans. - Yes it does. The FileNoFoundException is inherited from the IOException. Exception's subclasses have to be caught first.

Q. - What is the difference between yielding and sleeping?

Ans. - When a task invokes its yield() method, it returns to the ready state. When a task invokes its sleep() method, it returns to the waiting state.

Q. - Why Vector class is used?

Ans. - The Vector class provides the capability to implement a growable array of objects. Vector proves to be very useful if you don't know the size of the array in advance or you just need one that can change sizes over the lifetime of a program.

Q. - How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?

Ans. - Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16 and18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

Q. - What are Wrapper classes?

Ans. - These are classes that allow primitive types to be accessed as objects. Example: Integer, Character, Double, Boolean etc.

Q. - What is the difference between a Window and a Frame?

Ans. - The Frame class extends Window to define a main application window that can have a menu bar.

Q. - Which package has light weight components?

Ans. - javax.Swing package. All components in Swing except Japplet, Jdialog, JFrame and JWindow are lightweight components.

Q. - What is the difference between the paint() and repaint() methods?

Ans. - The paint() method supports painting via a Graphics object. The repaint() method is used to cause paint() to be invoked by the AWT painting thread.

Q. - What is the purpose of File class?

Ans. - It is used to create objects that provide access to the files and directories of a local file system.

Q. - What is the difference between the Reader/Writer class hierarchy and the InputStream/OutputStream class hierarchy?

Ans. - The Reader/Writer class hierarchy is character-oriented and the InputStream/OutputStream class hierarchy is byte-oriented.

Q. - Which class should you use to obtain design information about an object?

Ans. - The Class class is used to obtain information about an object's design and java.lang.Class class instance represent classes, interfaces in a running Java application.

Q. - What is the difference between static and non-static variables?

Ans. - A static variable is associated with the class as a whole rather than with specific instances of a class. Non-static variables take on unique values with each object instance.

Q. - What is Serialization and deserialization?

Ans. - Serialization is the process of writing the state of an object to a byte stream. Deserialization is the process of restoring these objects.

Q. - What are use cases?

Ans. - It is part of the analysis of a program and describes a situation that a program might encounter and what behavior the program should exhibit in that circumstance.

Q. - Explain the use of subclass in a Java program?

Ans. - Sub class inherits all the public and protected methods and the implementation. It also inherits all the default modifier methods and their implementation.

Q. - How to add menu shortcut to menu item?

Ans. - If there is a button instance called b1 you may add menu short cut by calling b1.setMnemonic('F') so the user may be able to use Alt+F to click the button.

Q. - Can you write a Java class that could be used both as an applet as well as an application?

Ans. - Yes just add a main() method to the applet.

Q. - What's the difference between constructors and other methods?

Ans. - Constructors must have the same name as the class and can not return a value. They are only called once while regular methods could be called many times.

Q. - Is there any limitation of using Inheritance?

Ans. - Yes since inheritance inherits everything from the super class and interface it may make the subclass too clustering and sometimes error-prone when dynamic overriding or dynamic overloading in some situation.

Q. - When is the ArrayStoreException thrown?

Ans. - When copying elements between different arrays if the source or destination arguments are not arrays or their types are not compatible an ArrayStoreException will be thrown.

Q. - Can you call one constructor from another if a class has multiple constructors?

Ans. - Yes use this() syntax.

Q. - What is a transient variable?

Ans. - A transient variable is a variable that may not be serialized during Serialization and which is initialized by its default value during de-serialization.

Q. - What is synchronization?

Ans. - Synchronization is the capability to control the access of multiple threads to shared resources. synchronized keyword in java provides locking which ensures mutual exclusive access of shared resource and prevent data race.

Q. - What is the Collections API?

Ans. - The Collections API is a set of classes and interfaces that support operations on collections of objects.

Q. - Does garbage collection guarantee that a program will not run out of memory?

Ans. - Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection.

Q. - Which Java operator is right associative?

Ans. - The = operator is right associative.

Q. - What is the difference between a break statement and a continue statement?

Ans. - A break statement results in the termination of the statement to which it applies (switch for do or while). A continue statement is used to end the current loop iteration and return control to the loop statement.

Q. - If a variable is declared as private, where may the variable be accessed?

Ans. - A private variable may only be accessed within the class in which it is declared.

Q. - What is the purpose of the System class?

Ans. - The purpose of the System class is to provide access to system resources.

Q. - List primitive Java types?

Ans. - The eight primitive types are byte, short, int, long, float, double, and boolean.

Q. - What class of exceptions are generated by the Java run-time system?

Ans. - The Java runtime system generates RuntimeException and Error exceptions.

Q. - Under what conditions is an object's finalize() method invoked by the garbage collector?

Ans. - The garbage collector invokes an object's finalize() method when it detects that the object has become unreachable.

Q. - How can a dead thread be restarted?

Ans. - A dead thread cannot be restarted.

Q. - Which arithmetic operations can result in the throwing of an ArithmeticException?

Ans. - Integer / and % can result in the throwing of an ArithmeticException.

Q. - Variable of the boolean type is automatically initialized as?

Ans. - The default value of the boolean type is false.

Q. - Can try statements be nested?

Ans. - Yes

Q. - What are ClassLoaders?

Ans. - A class loader is an object that is responsible for loading classes. The class ClassLoader is an abstract class.

Q. - What is the difference between an Interface and an Abstract class?

Ans. - An abstract class can have instance methods that implement a default behavior. An Interface can only declare constants and instance methods but cannot implement default behavior and all methods are implicitly abstract. An interface has all public members and no implementation.

Q. - What will happen if static modifier is removed from the signature of the main method?

Ans. - Program throws oSuchMethodError\ error at runtime.

Q. - What is the default value of an object reference declared as an instance variable?

Ans. - Null unless it is defined explicitly.

Q. - Can a top level class be private or protected?

Ans. - No a top level class cannot be private or protected. It can have either \public\ or no modifier.

Q. - Why do we need wrapper classes?

Ans. - We can pass them around as method parameters where a method expects an object. It also provides utility methods.

Q. - What is the difference between error and an exception?

Ans. - An error is an irrecoverable condition occurring at runtime. Such as OutOfMemory error. Exceptions are conditions that occur because of bad input etc. e.g. FileNotFoundException will be thrown if the specified file does not exist.

Q. - Is it necessary that each try block must be followed by a catch block?

Ans. - It is not necessary that each try block must be followed by a catch block. It should be followed by either a catch block or a finally block.

Q. - When a thread is created and started, what is its initial state?

Ans. - A thread is in the ready state as initial state after it has been created and started.

Q. - What is the Locale class?

Ans. - The Locale class is used to tailor program output to the conventions of a particular geographic political or cultural region.

Q. - What are synchronized methods and synchronized statements?

Ans. - Synchronized methods are methods that are used to control access to an object. A synchronized statement can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement.

Q. - What is runtime polymorphism or dynamic method dispatch?

Ans. - Runtime polymorphism or dynamic method dispatch is a process in which a call to an overridden method is resolved at runtime rather than at compile-time. In this process an overridden method is called through the reference variable of a superclass.

Q. - What is Dynamic Binding(late binding)?

Ans. - Binding refers to the linking of a procedure call to the code to be executed in response to the call. Dynamic binding means that the code associated with a given procedure call is not known until the time of the call at run -time.

Q. - Can constructor be inherited?

Ans. - No constructor cannot be inherited.

Q. - What are the advantages of ArrayList over arrays?

Ans. - ArrayList can grow dynamically and provides more powerful insertion and search mechanisms than arrays.

Q. - Why deletion in LinkedList is fast than ArrayList?

Ans. - Deletion in linked list is fast because it involves only updating the next pointer in the node before the deleted node and updating the previous pointer in the node after the deleted node.

Q. - How do you decide when to use ArrayList and LinkedList?

Ans. - If you need to frequently add and remove elements from the middle of the list and only access the list elements sequentially then LinkedList should be used. If you need to support random access without in serting or removing elements from any place other than the end, then ArrayList should be used.

Q. - What is a Values Collection View ?

Ans. - It is a collection returned by the values() method of the Map Interface It contains all the objects present as values in the map.

Q. - What is dot operator?

Ans. - The dot operator(.) is used to access the instance variables and methods of class objects. It is also used to access classes and sub-packages from a package.

Q. - Where and how can you use a private constructor?

Ans. - Private constructor is used if you do not want other classes to instantiate the object and to prevent subclassing.

Q. - What is type casting?

Ans. - Type casting means treating a variable of one type as though it is another type.

Q. - Describe life cycle of thread?

Ans. - A thread is an execution in a program. The life cycle of a thread include :- - Newborn state - Runnable state - Running state - Blocked state - Dead state

Q. - What is the difference between the >> and >>> operators?

Ans. - The >> operator carries the sign bit when shifting right. The >>> zero-fills bits that have been shifted out.

Q. - Which method of the Component class is used to set the position and size of a component?

Ans. - setBounds() method is used for this purpose.

Q. - What is the range of the short type?

Ans. - The range of the short type is -(2^15) to 2^15 - 1.

Q. - Does Java allow Default Arguments?

Ans. - No Java does not allow Default Arguments.

Q. - Which number is denoted by leading zero in java?

Ans. - Octal Numbers are denoted by leading zero in java example : 06

Q. - Which number is denoted by leading 0x or 0X in java?

Ans. - Hexadecimal Numbers are denoted by leading 0x or 0X in java example : 0XF

Q. - Break statement can be used as labels in Java?

Ans. - Yes For Example break one;

Q. - Where import statement is used in a Java program?

Ans. - Import statement is allowed at the beginning of the program file after package statement.

Q. - Explain suspend() method under Thread class.

Ans. - It is used to pause or temporarily stop the execution of the thread.

Q. - What is currentThread()?

Ans. - It is a public static method used to obtain a reference to the current thread.

Q. - Explain main thread under Thread class execution?

Ans. - The main thread is created automatically and it begins to execute immediately when a program starts. It ia thread from which all other child threads originate.

Q. - Define Network Programming?

Ans. - It refers to writing programs that execute across multiple devices (computers) in which the devices are all connected to each other using a network.

Q. - What is a Socket?

Ans. - Sockets provide the communication mechanism between two computers using TCP. A client program creates a socket on its end of the communication and attempts to connect that socket to a server.

Q. - Advantages of Java Sockets?

Ans. - Sockets are flexible and sufficient. Efficient socket based programming can be easily implemented for general communications. It cause low network traffic.

Q. - Disadvantages of Java Sockets?

Ans. - Socket based communications allows only to send packets of raw data between applications. Both the client-side and server-side have to provide mechanisms to make the data useful in any way.

Q. - Which class is used by server applications to obtain a port and listen for client requests?

Ans. - class is used by server applications to obtain a port and listen for client requests.

Q. - Which class represents the socket that both the client and server use to communicate with each other?

Ans. - class represents the socket that both the client and server use to communicate with each other.

Q. - Why Generics are used in Java?

Ans. - Generics provide compile-time type safety that allows programmers to catch invalid types at compile time. Java Generic methods and generic classes enable programmers to specify with a single method declaration a set of related me thods or, with a single class declaration, a set of related types.

Q. - What environment variables do I need to set on my machine in order to be able to run Java programs?

Ans. - CLASSPATH and PATH are the two variables.

Q. - Is there any need to import java.lang package?

Ans. - No there is no need to import this package. It is by default loaded internally by the JVM.

Q. - What is Nested top-level class?

Ans. - If a class is declared within a class and specify the static modifier the compiler treats the class just like any other top-level class. Nested top-level class is an Inner class.

Q. - What is Externalizable interface?

Ans. - Externalizable is an interface which contains two methods readExternal and writeExternal. These methods give you a control over the serialization mechanism.

Q. - If System.exit (0); is written at the end of the try block, will the finally block still execute?

Ans. - No in this case the finally block will not execute because when you say System.exit (0); the control immediately goes out of the program and thus finally never executes.

Q. - What is daemon thread?

Ans. - Daemon thread is a low priority thread which runs intermittently in the background doing the garbage collection operation for the java runtime system.

Q. - Which method is used to create the daemon thread?

Ans. - setDaemon method is used to create a daemon thread.

Q. - Which method must be implemented by all threads?

Ans. - All tasks must implement the run() method

Q. - What is the GregorianCalendar class?

Ans. - The GregorianCalendar provides support for traditional Western calendars.

Q. - What is the SimpleTimeZone class?

Ans. - The SimpleTimeZone class provides support for a Gregorian calendar.

Q. - What is the difference between the size and capacity of a Vector?

Ans. - The size is the number of elements actually stored in the vector while capacity is the maximum number of elements it can store at a given instance of time.

Q. - Can a vector contain heterogeneous objects?

Ans. - Yes a Vector can contain heterogeneous objects. Because a Vector stores everything in terms of Object.

Q. - What is an enumeration?

Ans. - An enumeration is an interface containing methods for accessing the underlying data structure from which the enumeration is obtained. It allows sequential access to all the elements stored in the collection.

Q. - What is difference between Path and Classpath?

Ans. - Path and Classpath are operating system level environment variables. Path is defines where the system can find the executables(.exe) files and classpath is used to specify the location of .class files.

Q. - Can a class declared as private be accessed outside it's package?

Ans. - No it's not possible to accessed outside it's package.

Q. - What are the restriction imposed on a static method or a static block of code?

Ans. - A static method should not refer to instance variables without creating an instance and cannot use \this\ operator to refer the instance.

Q. - Can an Interface extend another Interface?

Ans. - Yes an Interface can inherit another Interface for that matter an Interface can extend more than one Interface.

Q. - Which object oriented Concept is achieved by using overloading and overriding?

Ans. - Polymorphism

Q. - What is an object's lock and which object's have locks?

Ans. - An object's lock is a mechanism that is used by multiple threads to obtain synchronized access to the object. A thread may execute a synchronized method of an object only after it has acquired the object

Q. - What is Downcasting?

Ans. - It is the casting from a general to a more specific type i.e. casting down the hierarchy.

Q. - What are order of precedence and associativity and how are they used?

Ans. - Order of precedence determines the order in which operators are evaluated in expressions. Associativity determines whether an expression is evaluated left-to-right or right-to-left.

Q. - If a method is declared as protected, where may the method be accessed?

Ans. - A protected method may only be accessed by classes or interfaces of the same package or by subclasses of the class in which it is declared.

Q. - What is the difference between inner class and nested class?

Ans. - When a class is defined within a scope of another class then it becomes inner class. If the access modifier of the inner class is static then it becomes nested class.

Q. - What restrictions are placed on method overriding?

Ans. - Overridden methods must have the same name argument list and return type. The overriding method may not limit the access of the method it overrides.

Q. - What is constructor chaining and how is it achieved in Java?

Ans. - A child object constructor always first needs to construct its parent. In Java it is done via an implicit call to the no-args constructor as the first statement.

Q. - Can a double value be cast to a byte?

Ans. - Yes a double value can be cast to a byte.

Q. - Have you ever worked on a Java project ?

Ans. - - Mention project and advantages of the same - Mention the concepts learned

Q. - What is the MAIN benefit of designing tests early in the life cycle?

Ans. - It helps prevent defects from being introduced into the code.

Q. - What is risk-based testing?

Ans. - Risk-based testing is the term used for an approach to creating a test strategy that is based on prioritizing tests by risk. The basis of the approach is a detailed risk analysis and prioritizing of risks by risk level. Tests to address each risk are then specified, starting with the highest risk first.

Q. - What is the KEY difference between preventative and reactive approaches to testing?

Ans. - Preventative tests are designed early; reactive tests are designed after the software has been produced.

Q. - What is the purpose of exit criteria?

Ans. - The purpose of exit criteria is to define when a test level is completed.

Q. - What determines the level of risk?

Ans. - The likelihood of an adverse event and the impact of the event determine the level of risk.

Q. - When is used Decision table testing?

Ans. - Decision table testing is used for testing systems for which the specification takes the form of rules or cause-effect combinations. In a decision table the inputs are listed in a column, with the outputs in the same column but below the inputs. The remainder of the table explores combinations of inputs to define the outputs produced.

Q. - What is the MAIN objective when reviewing a software deliverable?

Ans. - To identify defects in any software work product.

Q. - Which defines the expected results of a test? Test case specification or test design specification.

Ans. - Test case specification defines the expected results of a test.

Q. - What is the benefit of test independence?

Ans. - It avoids author bias in defining effective tests.

Q. - As part of which test process do you determine the exit criteria?

Ans. - The exit criteria is determined on the bases of 'Test Planning'.

Q. - What is beta testing?

Ans. - Testing performed by potential customers at their own locations.

Q. - What is Rapid Application Development?

Ans. - Rapid Application Development (RAD) is formally a parallel development of functions and subsequent integration. Components/functions are developed in parallel as if they were mini projects the developments are time-boxed delivered and then assembled into a working prototype. This can very quickly give the customer something to see and use and to provide feedback regarding the delivery and their requirements. Rapid change and development of the product is possible using this methodology. However the product specification will need to be developed for the product at some point and the project will need to be placed under more formal controls prior to going into production.

Q. - What is the difference between Testing Techniques and Testing Tools?

Ans. - Testing technique :– Is a process for ensuring that some aspects of the application system or unit functions properly there may be few techniques but many tools. Testing Tools :– Is a vehicle for performing a test process. The tool is a resource to the tester but itself is insufficient to conduct testing.

Q. - What is component testing?

Ans. - Component testing also known as unit module and program testing searches for defects in and verifies the functioning of software (e.g. modules programs objects classes etc.) that are separately testable. Component testing may be done in isolation from the rest of the system depending on the context of the development life cycle and the system. Most often stubs and drivers are used to replace the missing software and simulate the interface between the software components in a simple manner. A stub is called from the software component to be tested; a driver calls a component to be tested.

Q. - What is functional system testing?

Ans. - Testing the end to end functionality of the system as a whole is defined as a functional system testing.

Q. - What are the benefits of Independent Testing?

Ans. - Independent testers are unbiased and identify different defects at the same time.

Q. - What are the different Methodologies in Agile Development Model?

Ans. - There are currently seven different agile methodologies that I am aware of: - Extreme Programming (XP) - Scrum - Lean Software Development - Feature-Driven Development - Agile Unified Process - Crystal - Dynamic Systems Development Model (DSDM)

Q. - What is random/monkey testing? When it is used?

Ans. - Random testing often known as monkey testing. In such type of testing data is generated randomly often using a tool or automated mechanism. With this randomly generated input the system is tested and results are analysed accordingly. These testing are less reliable; hence it is normally used by the beginners and to see whether the system will hold up under adverse effects.

Q. - Which are valid objectives for incident reports?

Ans. - - Provide developers and other parties with feedback about the problem to enable identification, isolation and correction as necessary. - Provide ideas for test process improvement. - Provide a vehicle for assessing tester competence. - Provide testers with a means of tracking the quality of the system under test.

Q. - Consider the following techniques. Which are static and which are dynamic techniques?

Ans. - Equivalence Partitioning - Use Case Testing - Data Flow Analysis - Exploratory Testing - Decision Testing - Inspections

Q. - What are the phases of a formal review?

Ans. - In contrast to informal reviews formal reviews follow a formal process. A typical formal review process consists of six main steps: - Planning - Kick-off - Preparation - Review meeting - Rework - Follow-up

Q. - What is the role of moderator in review process?

Ans. - The moderator (or review leader) leads the review process. He or she determines, in co-operation with the author,the type of review, approach and the composition of the review team. The moderator performs the entry check and the follow-up on the rework, in order to control the quality of the input and output of the review process. The moderator also schedules the meeting,disseminates documents before the meeting, coaches other team members,paces the meeting, leads possible discussions and stores the data that is collected.

Q. - What is an equivalence partition (also known as an equivalence class)?

Ans. - An input or output ranges of values such that only one value in the range becomes a test case.

Q. - What are the Structure-based (white-box) testing techniques?

Ans. - Structure-based testing techniques (which are also dynamic rather than static) use the internal structure of the software to derive test cases. They are commonly called 'white-box' or 'glass-box' techniques (implying you can see into the system) since they require knowledge of how the software is implemented that is how it works. For example a structural technique may be concerned with exercising loops in the software. Different test cases may be derived to exercise the loop once twice and many times. This may be done regardless of the functionality of the software.

Q. - When \Regression Testing\ should be performed?

Ans. - After the software has changed or when the environment has changed Regression testing should be performed.

Q. - What is negative and positive testing?

Ans. - A negative test is when you put in an invalid input and receives errors. While a positive testingis when you put in a valid input and expect some action to be completed in accordance with the specification.

Q. - What is the purpose of a test completion criterion?

Ans. - The purpose of test completion criterion is to determine when to stop testing.

Q. - What can static analysis NOT find?

Ans. - Memory leaks

Q. - What is the difference between re-testing and regression testing?

Ans. - Re-testing ensures the original fault has been removed; regression testing looks for unexpected side effects.

Q. - What are the Experience-based testing techniques?

Ans. - In experience-based techniques, people's knowledge, skills and background are a prime contributor to the test conditions and test cases. The experience of both technical and business people is important as they bring different perspectives to the test analysis and design process. Due to previous experience with similar systems they may have insights into what could go wrong which is very useful for testing.

Q. - An input field takes the year of birth between 1900 and 2004 what are the boundary values for testing this field?

Ans. - 1899 - 1900 2004 - 2000

Q. - What is the one Key reason why developers have difficulty testing their own work?

Ans. - Lack of Objectivity

Q. - How much testing is enough?

Ans. - The answer depends on the risk for your industry, contract and special requirements.

Q. - When should testing be stopped?

Ans. - It depends on the risks for the system being tested. There are some criteria bases on which you can stop testing :- - Deadlines (Testing Release) - Test budget has been depleted - Bug rate fall below certain level - Test cases completed with certain percentage passed - Alpha or beta periods for testing ends - Coverage of code, functionality or requirements are met to a specified point

Q. - Which is the main purpose of the integration strategy for integration testing in the small?

Ans. - The main purpose of the integration strategy is to specify which modules to combine when and how many at once.

Q. - What are semi-random test cases?

Ans. - Semi-random test cases are nothing but when we perform random test cases and do equivalence partitioning to those test cases, it removes redundant test cases, thus giving us semi-random test cases.

Q. - What is black box testing? What are the different black box testing techniques?

Ans. - Black box testing is the software testing method which is used to test the software without knowing the internal structure of code or program. This testing is usually done to check the functionality of an application. The different black box testing techniques are - Equivalence Partitioning - Boundary value analysis - Cause effect graphing

Q. - Why we use decision tables?

Ans. - The techniques of equivalence partitioning and boundary value analysis are often applied to specific situations or inputs. However, if different combinations of inputs result in different actions being taken, this can be more difficult to show using equivalence partitioning and boundary value analysis, which tend to be more focused on the user interface. The other two specification-based techniques, decision tables and state transition testing are more focused on business logic or business rules. A decision table is a good way to deal with combinations of things (e.g. inputs). This technique is sometimes also referred to as a 'cause-effect' table. The reason for this is that there is an associated logic diagramming technique called 'cause-effect graphing' which was sometimes used to help derive the decision table.

Q. - A number of critical bugs are fixed in software. All the bugs are in one module, related to reports. The test manager decides to do regression testing only on the reports module. Is it correct ?

Ans. - Regression testing should be done on other modules as well because fixing one module may affect other modules.

Q. - Why does the boundary value analysis provide good test cases?

Ans. - Because errors are frequently made during programming of the different cases near the 'edges' of the range of values.

Q. - What makes an inspection different from other review types?

Ans. - It is led by a trained leader, uses formal entry and exit criteria and checklists.

Q. - Why can be tester dependent on configuration management?

Ans. - Because configuration management assures that we know the exact version of the testware and the test object.

Q. - What is a V-Model?

Ans. - A software development model that illustrates how testing activities integrate with software development phases.

Q. - What is maintenance testing?

Ans. - Triggered by modifications, migration or retirement of existing software.

Q. - What is test coverage?

Ans. - Test coverage measures in some specific way the amount of testing performed by a set of tests (derived in some other way, e.g. using specification-based techniques). Wherever we can count things and can tell whether or not each of those things has been tested by some test, then we can measure coverage.

Q. - Why is incremental integration preferred over \big bang\ integration?

Ans. - Because incremental integration has better early defects screening and isolation ability.

Q. - When do we prepare RTM (Requirement traceability matrix), is it before test case designing or after test case designing?

Ans. - - It would be before test case designing. - Requirements should already be traceable from review activities since you should have traceability in the Test Plan already. - This question also would depend on the organisation. If the organisations do test after development started then requirements must be already traceable to their source. - To make life simpler use a tool to manage requirements.

Q. - What is called the process starting with the terminal modules?

Ans. - Bottom-up integration

Q. - During which test activity could faults be found most cost effectively?

Ans. - During test planning

Q. - What is the purpose of requirement phase ?

Ans. - To freeze requirements, to understand user needs, to define the scope of testing.

Q. - Why we split testing into distinct stages?

Ans. - We split testing into distinct stages because of following reasons, - Each test stage has a different purpose - It is easier to manage testing in stages - We can run different test into different environments - Performance and quality of the testing is improved using phased testing

Q. - What is DRE?

Ans. - To measure test effectiveness a powerful metric is used to measure test effectiveness known as DRE (Defect Removal Efficiency) From this metric we would know how many bugs we have found from the set of test cases. Formula for calculating DRE is DRE=Number of bugs while testing / number of bugs while testing + number of bugs found by user

Q. - How would you estimate the amount of re-testing likely to be required?

Ans. - Metrics from previous similar projects and discussions with the development team.

Q. - What studies data flow analysis?

Ans. - The use of data on paths through the code.

Q. - What is Alpha testing?

Ans. - Pre-release testing by end user representatives at the developer's site.

Q. - What are Test comparators?

Ans. - Is it really a test if you put some inputs into some software, but never look to see whether the software produces the correct result? The essence of testing is to check whether the software produces the correct result, and to do that, we must compare what the software produces to what it should produce. A test comparator helps to automate aspects of that comparison.

Q. - Who is responsible for document all the issues, problems and open point that were identified during the review meeting

Ans. - Scribe - is the person who does the logging of the defects found during a review.

Q. - What is the main purpose of Informal review ?

Ans. - Inexpensive way to get some benefit.

Q. - What is the purpose of test design technique?

Ans. - Identifying test conditions and Identifying test cases.

Q. - When testing a grade calculation system, a tester determines that all scores from 90 to 100 will yield a grade of A, but scores below 90 will not. This analysis is known as:

Ans. - Equivalence partitioning

Q. - During the testing of a module tester 'X' finds a bug and assigned it to developer. But developer rejects the same, saying that it's not a bug. What 'X' should do?

Ans. - Send to the detailed information of the bug encountered and check the reproducibility

Q. - A type of integration testing in which software elements hardware elements, or both are combined all at once into a component or an overall system, rather than in stages.

Ans. - Big-Bang Testing

Q. - In which order should tests be run?

Ans. - The most important one must tests first.

Q. - The later in the development life cycle a fault is discovered the more expensive it is to fix. Why?

Ans. - The fault has been built into more documentation, code, tests, etc.

Q. - What is Coverage measurement?

Ans. - It is a partial measure of test thoroughness.

Q. - What is Boundary value testing?

Ans. - Test boundary conditions on, below and above the edges of input and output equivalence classes. For instance, let say a bank application where you can withdraw maximum Rs.20,000 and a minimum of Rs.100, so in boundary value testing we test only the exact boundaries, rather than hitting in the middle. That means we test above the maximum limit and below the minimum limit.

Q. - What is Fault Masking?

Ans. - Error condition hiding another error condition.

Q. - What does COTS represent?

Ans. - Commercial off The Shelf

Q. - What is the purpose of Test Environment ?

Ans. - The purpose of Test Environment is to allow specific tests to be carried out on a system or network that resembles as closely as possible the environment where the item under test will be used upon release.

Q. - What can be thought of as being based on the project plan, but with greater amounts of detail?

Ans. - Phase Test Plan

Q. - What is exploratory testing?

Ans. - Exploratory testing is a hands-on approach in which testers are involved in minimum planning and maximum test execution. The planning involves the creation of a test charter, a short declaration of the scope of a short (1 to 2 hour) time-boxed test effort, the objectives and possible approaches to be used. The test design and test execution activities are performed in parallel typically without formally documenting the test conditions, test cases or test scripts. This does not mean that other, more formal testing techniques will not be used. For example, the tester may decide to use boundary value analysis but will think through and test the most important boundary values without necessarily writing them down. Some notes will be written during the exploratory-testing session, so that a report can be produced afterwards.

Q. - What is \use case testing\?

Ans. - In order to identify and execute the functional requirement of an application from start to finish \use case\ is used and the techniques used to do this is known as \Use Case Testing\.

Q. - What is the difference between STLC (Software Testing Life Cycle) and SDLC (Software Development Life Cycle) ?

Ans. - The complete Verification and Validation of software is done in SDLC, while STLC only does Validation of the system.

Q. - What is traceability matrix?

Ans. - The relationship between test cases and requirements is shown with the help of a document. This document is known as traceability matrix.

Q. - What is Equivalence partitioning testing?

Ans. - Equivalence partitioning testing is a software testing technique which divides the application input test data into each partition at least once of equivalent data from which test cases can be derived. By this testing method it reduces the time required for software testing.

Q. - What is white box testing and list the types of white box testing?

Ans. - White box testing technique involves selection of test cases based on an analysis of the internal structure (Code coverage, branches coverage, paths coverage, condition coverage etc.) of a component or system. It is also known as Code-Based testing or Structural testing. Different types of white box testing are - Statement Coverage - Decision Coverage

Q. - In white box testing what do you verify?

Ans. - In white box testing following steps are verified. - Verify the security holes in the code - Verify the incomplete or broken paths in the code - Verify the flow of structure according to the document specification - Verify the expected outputs - Verify all conditional loops in the code to check the complete functionality of the application - Verify the line by line coding and cover 100% testing

Q. - What is the difference between static and dynamic testing?

Ans. - Static testing : During Static testing method, the code is not executed and it is performed using the software documentation. Dynamic testing : To perform this testing the code is required to be in an executable form.

Q. - What is verification and validation?

Ans. - Verification is a process of evaluating software at development phase and to decide whether the product of a given application satisfies the specified requirements. Validation is the process of evaluating software at the end of the development process and to check whether it meets the customer requirements.

Q. - What are different test levels?

Ans. - There are four test levels :- - Unit/component/program/module testing - Integration testing - System testing - Acceptance testing

Q. - What is Integration testing?

Ans. - Integration testing is a level of software testing process, where individual units of an application are combined and tested. It is usually performed after unit and functional testing.

Q. - What are the tables in testplans?

Ans. - Test design, scope, test strategies , approach are various details that Test plan document consists of. - Test case identifier - Scope - Features to be tested - Features not to be tested - Test strategy & Test approach - Test deliverables - Responsibilities - Staffing and training - Risk and Contingencies

Q. - What is the difference between UAT (User Acceptance Testing) and System testing?

Ans. - System Testing : system Testing is finding defects when the system under goes Testing as a whole, it is also known as end to end testing. In such type of Testing, the application undergoes from beginning till the end. UAT : User Acceptance Testing (UAT) involves running a product through a series of specific tests which determines whether the product will meet the needs of its users.

Q. - Mention the difference between Data Driven Testing and Retesting.

Ans. - Retesting : It is a process of checking bugs that are actioned by development team to verify that they are actually fixed. Data Driven Testing (DDT) : In Data Driven Testing process, application is tested with multiple test data. application is tested with different set of values.

Q. - What are the valuable steps to resolve issues while testing?

Ans. - - Record : Log and handle any problems which has happened - Report : Report the issues to higher level manager - Control : Define the issue management process

Q. - What is the difference between test scenarios, test cases and test script?

Ans. - Difference between test scenarios and test cases is , it includes plans for testing productthat Test Scenarios : Test scenario is prepared before the actual testing starts, number of team members, environmental condition, making test cases, making test plans and all the features that are to be tested for the product. Test Cases : It is a document that contains the steps that has to be executed,it has been planned earlier. Test Script : It is written in a programming language and it's a short program used to test part of functionality of the software system. In other words a written set of steps that should be performed manually.

Q. - What is Latent defect?

Ans. - This defect is an existing defect in the system which does not cause any failure as the exact set of conditions has never been met.

Q. - What are the two parameters which can be useful to know the quality of test execution?

Ans. - To know the quality of test execution we can use two parameters :- - Defect reject ratio - Defect leakage ratio

Q. - What is the function of software testing tool \phantom\?

Ans. - Phantom is a freeware, and is used for windows GUI automation scripting language. It allows to take control of windows and functions automatically. It can simulate any combination of key strokes and mouse clicks as well as menus, lists and more.

Q. - Explain what is Test Deliverables ?

Ans. - Test Deliverables are set of documents, tools and other components that has to be developed and maintained in support of testing. There are different test deliverables at every phase of the software development lifecycle :- - Before Testing - During Testing - After the Testing

Q. - What is mutation testing?

Ans. - Mutation testing is a technique to identify if a set of test data or test case is useful by intentionally introducing various code changes (bugs) and retesting with original test data/ cases to determine if the bugs are detected.

Q. - What all things you should consider before selecting automation tools for the AUT?

Ans. - - Technical Feasibility - Complexity level - Application stability - Test Data - Application size - Re-usability of automated scripts - Execution across environment

Q. - How will you conduct Risk Analysis?

Ans. - For the risk analysis following steps need to be implemented (a) Finding the score of the risk (b) Making a profile for the risk (c) Changing the risk properties (d) Deploy the resources of that test risk (e) Making a database of risk

Q. - What are the categories of debugging?

Ans. - Categories for debugging (a) Brute force debugging (b) Backtracking (c) Cause elimination (d) Program slicing (e) Fault tree analysis

Q. - What is fault masking explain with example?

Ans. - - When presence of one defect hides the presence of another defect in the system is known as fault masking. - For Example, If the egative Value\ cause a firing of unhandled system exception, the developer will prevent the negative values input. - This will resolve the issue and hide the defect of unhandled exception firing.

Q. - Explain what is Test Plan ? What are the information that should be covered in Test Plan ?

Ans. - A test plan can be defined as a document describing the scope, approach, resources and schedule of testing activities and a test plan should cover the following details. - Test Strategy - Test Objective - Exit/Suspension Criteria - Resource Planning - Test Deliverables

Q. - How you can eliminate the product risk in your project ?

Ans. - To eliminate product risk in your project, there is simple yet crucial step that can reduce the product risk in your project. - Investigate the specification documents - Have discussions about the project with all stakeholders including the developer - As a real user walk around the website

Q. - What are the common risk that leads to the project failure?

Ans. - The common risk that leads to a project failure are - Not having enough human resource - Testing Environment may not be set up properly - Limited Budget - Time Limitations

Q. - On what basis you can arrive to an estimation for your project?

Ans. - To estimate your project, you have to consider following points :- - Divide the whole project into a smallest tasks - Allocate each task to team members - Estimate the effort required to complete each task - Validate the estimation

Q. - Explain how you would allocate task to team members ?

Ans. - 1. Analyze software requirement specification - All the members 2. Create the test specification - Tester/Test Analyst 3. Build up the test environment - Test administrator 4. Execute the test cases - Tester, Test administrator 5. Report defects - Tester

Q. - Explain what is testing type and what are the commonly used testing type ?

Ans. - To get an expected test outcome a standard procedure is followed which is referred as Testing Type. Commonly used testing types are :- - Unit Testing : Test the smallest code of an application - API Testing : Testing API created for the application - Integration Testing : Individual software modules are combined and tested - System Testing : Complete testing of system - Install/UnInstall Testing : Testing done from the point of client/customer view - Agile Testing : Testing through Agile technique

Q. - While monitoring your project what all things you have to consider ?

Ans. - The things that has to be taken in considerations are - Is you project on schedule - Are you over budget - Are you working towards the same career goal - Have you got enough resources - Are there any warning signs of impending problems - Is there any pressure from management to complete the project sooner

Q. - What are the common mistakes which creates issues ?

Ans. - - Matching resources to wrong projects - Test manager lack of skills - Not listening to others - Poor Scheduling - Underestimating - Ignoring the small problems - Not following the process

Q. - What does a typical test report contains? What are the benefits of test reports?

Ans. - A test report contains following things :- - Project Information - Test Objective - Test Summary - Defect The benefits of test reports are :- - Current status of project and quality of product are informed - If required, stake holder and customer can take corrective action - A final document helps to decide whether the product is ready for release

Q. - What is test management review and why it is important?

Ans. - Management review is also referred as Software Quality Assurance or SQA. SQA focuses more on the software process rather than the software work products. It is a set of activities designed to make sure that the project manager follows the standard process. SQA helps test manager to benchmark the project against the set standards.

Q. - What are the best practices for software quality assurance?

Ans. - The best practices for an effective SQA implementation is :- - Continuous Improvement - Documentation - Tool Usage - Metrics - Responsibility by team members - Experienced SQA auditors

Q. - When is RTM (Requirement Traceability Matrix) prepared ?

Ans. - RTM is prepared before test case designing. Requirements should be traceable from review activities.

Q. - What is difference between Test matrix and Traceability matrix?

Ans. - Test Matrix : Test matrix is used to capture actual quality, effort, the plan, resources and time required to capture all phases of software testing. Traceability Matrix : Mapping between test cases and customer requirements is known as Traceability Matrix.

Q. - In manual testing what are stubs and drivers?

Ans. - Both stubs and drivers are part of incremental testing. In incremental testing there are two approaches namely bottom up and top down approach. Drivers are used in bottom up testing and stub is used for top down approach. In order to test the main module, stub is used, which is a dummy code or program.

Q. - What are the step you would follow once you find the defect?

Ans. - Once defect is found you would follow the step :- (a) Recreate the defect (b) Attach the screen shot (c) Log the defect

Q. - Explain what is \Test Plan Driven\ or \Key Word Driven\ method of testing?

Ans. - This technique uses the actual test case document developed by testers using a spread sheet containing special \key Words\. The key words control the processing.

Q. - What is DFD (Data Flow Diagram) ?

Ans. - When a \flow of data\ through an information system is graphically represented then it is known as Data Flow Diagram. It is also used for the visualization of data processing.

Q. - Explain what is LCSAJ?

Ans. - LCSAJ stands for 'linear code sequence and jump'. It consists of the following three items :- (a) Start of the linear sequence of executable statements (b) End of the linear sequence (c) The target line to which control flow is transferred at the end of the linear sequence

Q. - Explain what is N+1 testing?

Ans. - The variation of regression testing is represented as N+1. In this technique the testing is performed in multiple cycles in which errors found in test cycle 'N' are resolved and re-tested in test cycle N+1. The cycle is repeated unless there are no errors found.

Q. - What is Fuzz testing and when it is used?

Ans. - Fuzz testing is used to detect security loopholes and coding errors in software. In this technique random data is added to the system in attempt to crash the system. If vulnerability persists, a tool called fuzz tester is used to determine potential causes. This technique is more useful for bigger projects but only detects major fault.

Q. - Mention what are the main advantages of statement coverage metric of software testing?

Ans. - The benefit of statement coverage metric is that :- (a) It does not require processing source code and can be applied directly to object code. (b) Bugs are distributed evenly through code, due to which percentage of executable statements covered reflects the percentage of faults discovered.

Q. - How to generate test cases for replace string method?

Ans. - (A) If characters in new string > characters in previous string. - None of the characters should get truncated (B) If characters in new string< characters in previous string. - Junk characters should not be added (C) Spaces after and before the string should not be deleted (D) String should be replaced only for the first occurrence of the string

Q. - How will you handle a conflict amongst your team members ?

Ans. - - I will talk individually to each person and note their concerns. - I will find solution to the common problems raised by team members. - I will hold a team meeting, reveal the solution and ask people to co-operate.

Q. - Mention what are the categories of defects?

Ans. - Mainly there are three defect categories :- Wrong : When requirement is implemented incorrectly Missing : It is a variance from the specification, an indication that a specification was not implemented or a requirement of the customer is not met Extra : A requirement incorporated into the product that was not given by the end customer. It is considered as a defect because it is a variance from the existing requirements

Q. - Explain how does a test coverage tool works?

Ans. - The code coverage testing tool runs parallel while performing testing on the actual product. The code coverage tool monitors the executed statements of the source code. When the final testing is done we get a complete report of the pending statements and also get the coverage percentage.

Q. - Mention what is the difference between a \defect\ and a \failure\ in software testing?

Ans. - In simple terms when a defect reaches the end customer it is called a failure while the defect is identified internally and resolved then it is referred as defect.

Q. - Explain how to test documents in a project that span across the software development lifecycle ?

Ans. - The project span across the software development lifecycle in following manner :- Central/Project test plan : It is the main test plan that outlines the complete test strategy of the project. This plan is used till the end of the software development lifecycle. Acceptance test plan : This document begins during the requirement phase and is completed at final delivery. System test plan : This plan starts during the design plan and proceeds until the end of the project. Integration and Unit test plan : Both these test plans start during the execution phase and last until the final delivery.

Q. - Explain which test cases are written first black boxes or white boxes ?

Ans. - Black box test cases are written first as to write black box test cases; it requires project plan and requirement document all these documents are easily available at the beginning of the project. While writing white box test cases requires more architectural understanding and is not available at the start of the project.

Q. - Explain what is the difference between latent and masked defects?

Ans. - Latent defect : A latent defect is an existing defect that has not caused a failure because the sets of conditions were never met Masked defect : It is an existing defect that has not caused a failure because another defect has prevented that part of the code from being executed

Q. - Mention what is bottom up testing?

Ans. - Bottom up testing is an approach to integration testing, where the lowest level components are tested first, then used to facilitate the testing of higher level components. The process is repeated until the component at the top of the hierarchy is tested.

Q. - Mention what are the different types of test coverage techniques ?

Ans. - Different types of test coverage techniques include :- Statement Coverage : It verifies that each line of source code has been executed and tested. Decision Coverage : It ensures that every decision in the source code is executed and tested. Path Coverage : It ensures that every possible route through a given part of code is executed and tested.

Q. - Mention what is the meaning of breadth testing?

Ans. - Breadth testing is a test suite that exercises the full functionality of a product but does not test features in detail.

Q. - Mention what is the difference between Pilot and Beta testing?

Ans. - The difference between pilot and beta testing is that pilot testing is actually done using the product by the group of user before the final deployment and in beta testing we do not input real data, but it is installed at the end customer to validate if the product can be used in production.

Q. - Explain what is the meaning of Code Walk Through?

Ans. - Code Walk Through is the informal analysis of the program source code to find defects and verify coding techniques

Q. - Mention what are the basic components of defect report format ?

Ans. - The basic components of defect report format includes :- - Project Name - Module Name - Defect detected on - Defect detected by - Defect ID and Name - Snapshot of the defect - Priority and Severity status - Defect resolved by - Defect resolved on

Q. - Mention what is the purpose behind doing end-to-end testing?

Ans. - End-to end testing is done after functional testing. The purpose behind doing end-to-end testing is that - To validate the software requirements and integration with external interfaces - Testing application in real world environment scenario - Testing of interaction between application and database

Q. - Explain what it meant by test harness?

Ans. - A test harness is configuring a set of tools and test data to test an application in various conditions, it involves monitoring the output with expected output for correctness.

Q. - Explain in a testing project what testing activities would you automate?

Ans. - In a testing project testing activities you would automate are :- - Tests that need to be run for every build of the application - Tests that use multiple data for the same set of actions - Identical tests that needs to be executed using different browsers - Mission critical pages - Transaction with pages that do not change in short time

Q. - Have you ever worked on a Testing Project ?

Ans. - - Mention project and advantages of the same - Mention the concepts learned

Q. - What are the advantages of using cloud computing?

Ans. - The advantages of using cloud computing are a) Data backup and storage of data b) Powerful server capabilities c) SaaS ( Software as a service) d) Information technology sandboxing capabilities e) Increase in productivity f) Cost effective & Time saving

Q. - Mention platforms which are used for large scale cloud computing?

Ans. - The platforms that are used for large scale cloud computing are a) Apache Hadoop b) MapReduce

Q. - Explain different models for deployment in cloud computing?

Ans. - The different deployment models in cloud computing are a) Private Cloud b) Public Cloud c) Community Cloud d) Hybrid Cloud

Q. - What is the difference in cloud computing and computing for mobiles?

Ans. - Mobile computing uses the same concept as cloud computing. Cloud computing becomes active with the data with the help of internet rather than individual device. It provides users with the data which they have to retrieve on demand. In mobile, the applications runs on the remote server and gives user the access for storage and manage.

Q. - How user can gain from utility computing?

Ans. - Utility computing allows the user to pay only for what they are using. It is a plug-in managed by an organization which decides what type of services has to be deployed from the cloud. Most organizations prefer hybrid strategy.

Q. - For a transport in cloud how you can secure your data?

Ans. - To secure your data while transporting them from one place to another, check that there is no leak with the encryption key implemented with the data you are sending.

Q. - What are the security aspects provided with cloud?

Ans. - a) Identity management: It authorizes the application services b) Access control: permission has to be provided to the users so that they can control the access of another user who is entering into the cloud environment. c) Authentication and Authorization: Allows only the authorized and authenticated user only to access the data and applications

Q. - List out different layers which define cloud architecture?

Ans. - The different layers used by cloud architecture are a) CLC or Cloud Controller b) Walrus c) Cluster Controller d) SC or Storage Controller e) NC or Node Controller

Q. - What are system integrators in Cloud Computing?

Ans. - In Cloud Computing, systems integrator provides the strategy of the complicated process used to design a cloud platform. Integrator allows to create more accurate hybrid and private cloud network, as integrators have all the knowledge about the data center creation.

Q. - What is " EUCALYPTUS" stands for?

Ans. - " EUCALYPTUS" stands for Elastic Utility Computing Architecture For Linking Your Programs To Useful Systems"

Q. - Explain what is the use of "EUCALYPTUS" in cloud computing?

Ans. - "Eucalyptus" is an open source software infrastructure in cloud computing, which is used to implement clusters in cloud computing platform. It is used to build public, hybrid and private clouds. It has the ability to produce your own data center into a private cloud and allows you to use its functionality to many other organizations.

Q. - What is the requirement of virtualization platform in implementing cloud?

Ans. - The requirement of virtualization platform in implementing cloud is to a) Manage the service level policies b) Cloud Operating System c) Virtualization platforms helps to keep the backend level and user level concepts different from each other

Q. - Before going for cloud computing platform what are the essential things to be taken in concern by users?

Ans. - a) Compliance b) Loss of data c) Data storage d) Business continuity e) Uptime f) Data integrity in cloud computing

Q. - Mention some open source cloud computing platform databases?

Ans. - The open source cloud computing platform databases are a) MongoDB b) CouchDB c) LucidDB

Q. - What are the security laws which are implemented to secure data in a cloud ?

Ans. - The security laws which are implemented to secure data in cloud are a) Processing: Control the data that is being processed correctly and completely in an application b) File: It manages and control the data being manipulated in any of the file c) Output reconciliation: It controls the data which has to be reconciled from input to output d) Input Validation: Control the input data e) Security and Backup: It provides security and backup it also controls the security breaches logs

Q. - Mention the name of some large cloud providers and databases?

Ans. - a) Google bigtable b) Amazon simpleDB c) Cloud based SQL

Q. - Explain the difference between cloud and traditional datacenters?

Ans. - a) The cost of the traditional data center is higher due to heating and hardware/software issues b) Cloud gets scaled when the demand increases. Majority of the expenses are spent on the maintenance of the data centers, while that is not the case with cloud computing

Q. - Explain what are the different modes of software as a service (SaaS)?

Ans. - a) Simple multi-tenancy : In this each user has independent resources and are different from other users, it is an efficient mode. b) Fine grain multi-tenancy: In this type, the resources can be shared by many but the functionality remains the same.

Q. - What is the use of API's in cloud services?

Ans. - API's ( Application Programming Interface) is very useful in cloud platforms a) It eliminates the need to write the fully fledged programs b) It provides the instructions to make communication between one or more applications c) It allows easy creation of applications and link the cloud services with other systems

Q. - What are the different data centers deployed for cloud computing?

Ans. - Cloud computing consists of different datacenters like a) Containerized Datacenters b) Low Density Datacenters

Q. - In cloud computing what are the different layers?

Ans. - The different layers of cloud computing are: a) SaaS: Software as a Service (SaaS), it provides users access directly to the cloud application without installing anything on the system. b) IaaS: Infrastructure as a service, it provides the infrastructure in terms of hardware like memory, processor speed etc. c) PaaS: Platform as a service, it provides cloud application platform for the developers

Q. - How important is the platform as a service?

Ans. - Platform as a service or PAAS is an important layer in cloud computing. It provides application platform for providers. It is responsible for providing complete virtualization of the infrastructure layer and makes it work like a single server.

Q. - What is a cloud service?

Ans. - Cloud service is used to build cloud applications using the server in a network through internet. It provides the facility of using the cloud application without installing it on the computer. It also reduces the maintenance and support of the application which are developed using cloud service.

Q. - List down the three basic clouds in cloud computing?

Ans. - a) Professional cloud b) Personal cloud c) Performance cloud

Q. - As a infrastructure as a service what are the resources that are provided by it?

Ans. - IAAS ( Infrastructure As A Service) provides virtual and physical resources that are used to build a cloud. It deals with the complexities of deploying and maintaining of the services provided by this layer. Here the infrastructure is the servers, storage and other hardware systems.

Q. - What are the business benefits involved in cloud architecture?

Ans. - The benefits involved in cloud architecture is a) Zero infrastructure investment b) Just in time infrastructure c) More efficient resource utilization

Q. - What are the characteristics of cloud architecture that separates it from traditional one?

Ans. - The characteristics that makes cloud architecture above traditional architecture is a) According to the demand cloud architecture provides the hardware requirement b) Cloud architecture is capable of scaling the resource on demand c) Cloud architecture is capable of managing and handling dynamic workloads without failure

Q. - Mention what is the difference between elasticity and scalability in cloud computing?

Ans. - Scalability is a characteristics of cloud computing through which increasing workload can be handled by increasing in proportion the amount of resource capacity. Whereas, elasticity, is being one of the characteristics that highlights the concept of commissioning and decommissioning of a large amount of resource capacity.

Q. - Mention the services that are provided by Window Azure Operating System?

Ans. - Window Azure provides three core services which are given as a) Compute b) Storage c) Management

Q. - In cloud architecture what are the different components that are required?

Ans. - a) Cloud Ingress b) Processor Speed c) Cloud storage services d) Cloud provided services e) Intra-cloud communications

Q. - In cloud architecture what are the different phases involved?

Ans. - a) Launch Phase b) Monitor Phase c) Shutdown Phase d) Cleanup Phase

Q. - List down the basic characteristics of cloud computing?

Ans. - a) Elasticity and Scalability b) Self-service provisioning and automatic de-provisioning c) Standardized interfaces d) Billing self service based usage model

Q. - In cloud architecture what are the building blocks?

Ans. - a) Reference architecture b) Technical architecture c) Deployment operation architecture

Q. - Mention in what ways cloud architecture provide automation and performance transparency?

Ans. - To provide the performance transparency and automation there are many tools used by cloud architecture. It allows to manage the cloud architecture and monitor reports. It also allows them to share the application using the cloud architecture. Automation is the key component of cloud architecture which helps to improve the degree of quality.

Q. - In cloud computing explain the role of performance cloud?

Ans. - Performance cloud is useful in transferring maximum amount of data instantly. It is used by the professionals who work on high performance computing research.

Q. - Explain hybrid and community cloud?

Ans. - Hybrid cloud: It consists of multiple service providers. It is a combination of public and private cloud features. It is used by the company when they require both private and public clouds both. Community Cloud: This model is quite expensive and is used when the organizations having common goals and requirements, and are ready to share the benefits of the cloud service.

Q. - In cloud what are the optimizing strategies?

Ans. - To overcome the maintenance cost and to optimize the resources ,there is a concept of three data center in cloud which provides recovery and back-up in case of disaster or system failure and keeps all the data safe and intact.

Q. - What is Amazon SQS?

Ans. - To communicate between different connectors Amazon SQS message is used, between various components of AMAZON, it acts as a communicator.

Q. - How buffer is used to Amazon web services?

Ans. - In order to make system more efficient against the burst of traffic or load, buffer is used. It synchronizes different component . The component always receives and processes the request in an unbalanced way. The balance between different components are managed by buffer, and makes them work at the same speed to provide faster services.

Q. - Mention what is Hypervisor in cloud computing and their types?

Ans. - Hypervisor is a Virtual Machine Monitor which manages resources for virtual machines. There are mainly two types of hypervisors Type 1: The guest Vm runs directly over the host hardware, eg Xen, VmWare ESXI Type 2: The guest Vm runs over hardware through a host OS, eg Kvm, oracle virtualbox

Q. - What are the advantages of Angular4/5?

Ans. - Advantages of AngularJS are, - AngularJS provides capability to create Single Page Application in a very clean and maintainable way. - AngularJS provides data binding capability to HTML thus giving user a rich and responsive experience. - AngularJS code is unit testable. - AngularJS uses dependency injection and make use of separation of concerns. - AngularJS provides reusable components. - With AngularJS, developer writes less code and gets more functionality. - In AngularJS, views are pure html pages, and controllers written in JavaScript do the business processing. - AngularJS applications can run on all major browsers and smart phones including Android and iOS based phones/tablets.

Q. - What is data-binding in Angular 4/5 ?

Ans. - Data binding is the automatic synchronization of data between model and view components. ng-model directive is used in data binding.

Q. - What is scope in Angular 4/5 ?

Ans. - Scopes are objects that refer to the model. They act as glue between controller and view.

Q. - What are the controllers in Angular 4/5 ?

Ans. - Controllers are JavaScript functions that are bound to a particular scope. They are the prime actors in AngularJS framework and carry functions to operate on data and decide which view is to be updated to show the updated model based data.

Q. - What are the services in Angular 4/5 ?

Ans. - AngularJS come with several built-in services. For example $http service is used to make XMLHttpRequests (Ajax calls). Services are singleton objects which are instantiated only once in app.

Q. - What are the filters in Angular 4/5 ?

Ans. - Filters select a subset of items from an array and return a new array. Filters are used to show filtered items from a list of items based on defined criteria.

Q. - What are the disadvantages of Angular4/5?

Ans. - Disadvantages of AngularJS, - Not Secure − Being JavaScript only framework, application written in AngularJS are not safe. Server side authentication and authorization is must to keep an application secure. - Not degradable − If your application user disables JavaScript then user will just see the basic page and nothing more.

Q. - Which are the core directives of Angular4/5?

Ans. - Three core directives of AngularJS. - ng-app − This directive defines and links an AngularJS application to HTML. - ng-model − This directive binds the values of AngularJS application data to HTML input controls. - ng-bind − This directive binds the AngularJS Application data to HTML tags.

Q. - Explain Templates in Angular4/5.

Ans. - Templates are the rendered view with information from the controller and model. These can be a single file (like index.html) or multiple views in one page using partials.

Q. - Explain AngularJS boot process.

Ans. - - When the page is loaded in the browser, following things happen: - HTML document is loaded into the browser, and evaluated by the browser. - AngularJS JavaScript file is loaded; the angular global object is created. Next, JavaScript which register

Q. - What is MVC?

Ans. - Model View Controller or MVC as it is popularly called, is a software design pattern for developing web applications. A Model View Controller pattern is made up of the following three parts : - Model − It is the lowest level of the pattern responsible for maintaining data. - View − It is responsible for displaying all or a portion of the data to the user. - Controller − It is a software Code that controls the interactions between the Model and View.

Q. - Explain ng-model directive.

Ans. - ng-model directive binds the values of AngularJS application data to HTML input controls. It creates a model variable which can be used with the html page and within the container control(for example, div) having ng-app directive.

Q. - Explain ng-app directive.

Ans. - ng-app directive defines and links an AngularJS application to HTML. It also indicates the start of the application.

Q. - Explain ng-bind directive.

Ans. - ng-bind directive binds the AngularJS Application data to HTML tags. ng-bind updates the model created by ng-model directive to be displayed in the html tag whenever user input something in the control or updates the html control's data when model data is updated by controller.

Q. - Explain ng-controller directive.

Ans. - ng-controller directive tells AngularJS what controller to use with this view. AngularJS application mainly relies on controllers to control the flow of data in the application. A controller is a JavaScript object containing attributes/properties and functions. Each controller accepts $scope as a parameter which refers to the application/module that controller is to control.

Q. - How AngularJS integrates with HTML?

Ans. - AngularJS being a pure javaScript based library integrates easily with HTML. - Step 1 − Include angularjs javascript library in the html page. - Step 2 − Point to AngularJS app - Next we tell what part of the HTML contains the AngularJS app. This done by adding the ng-app attribute to the root HTML element of the AngularJS app. You can either add it to html element or body element

Q. - What are Angular JS expressions ?

Ans. - Expressions are used to bind application data to html. Expressions are written inside double braces like {{expression}}. Expressions behave in same way as ng-bind directives. AngularJS application expressions are pure JavaScript expressions and outputs the data where they are used.

Q. - How do you make Ajax call using Angular 4/5 ?

Ans. - AngularJS provides $http control which works as a service to make ajax call to read data from the server. The server makes a database call to get the desired records. AngularJS needs data in JSON format. Once the data is ready, $http can be used to get the data from server.

Q. - What is $rootScope ?

Ans. - Scope is a special JavaScript object which plays the role of joining controller with the views. Scope contains the model data. In controllers, model data is accessed via $scope object. $rootScope is the parent of all of the scope variables.

Q. - Is Angular JS extensible ?

Ans. - Yes! In AngularJS we can create custom directive to extend AngularJS existing functionalities. Custom directives are used in AngularJS to extend the functionality of HTML. Custom directives are defined using directive function. A custom directive simply replaces the element for which it is activated. AngularJS application during bootstrap finds the matching elements and do one time activity using its compile() method of the custom directive then process the element using link() method of the custom directive based on the scope of the directive.

Q. - How to implement internationalization in Angular 4/5 ?

Ans. - AngularJS supports inbuilt internationalization for three types of filters currency, date and numbers. We only need to incorporate corresponding js according to locale of the country. By default it handles the locale of the browser.

Q. - Explain ng-init directive.

Ans. - ng-init directive initializes an AngularJS Application data. It is used to put values to the variables to be used in the application.

Q. - Explain ng-repeat directive.

Ans. - ng-repeat directive repeats html elements for each item in a collection.

Q. - Explain lowercase filter.

Ans. - Lowercase filter converts a text to lower case text.

Q. - Explain currency filter.

Ans. - Currency filter formats text in a currency format.

Q. - Explain orderby filter.

Ans. - orderby filter orders the array based on provided criteria.

Q. - Explain ng-disabled directive.

Ans. - ng-disabled directive disables a given control.

Q. - Explain ng-show directive.

Ans. - ng-show directive shows a given control.

Q. - Explain ng-hide directive.

Ans. - ng-hide directive hides a given control.

Q. - Explain ng-click directive.

Ans. - ng-click directive represents a AngularJS click event.

Q. - What is a service?

Ans. - Services are JavaScript functions and are responsible to do specific tasks only. Each service is responsible for a specific task for example, $http is used to make ajax call to get the server data. $route is used to define the routing information and so on. Inbuilt services are always prefixed with $ symbol.

Q. - What is service method?

Ans. - Using service method, we define a service and then assign method to it. We've also injected an already available service to it. mainApp.service('CalcService', function(MathService){ \t this.square = function(a) { \t return MathService.multiply(a,a); \t } });

Q. - What is factory method?

Ans. - Using factory method, we first define a factory and then assign method to it. var mainApp = angular.module(\, []); mainApp.factory('MathService', function() { \t var factory = {}; \t factory.multiply = function(a, b) { \t return a * b } return factory; });

Q. - What are the differences between service and factory methods?

Ans. - Factory method is used to define a factory which can later be used to create services as and when required whereas service method is used to create a service whose purpose is to do some defined task.

Q. - Which components can be injected as a dependency in AngularJS?

Ans. - AngularJS provides a supreme Dependency Injection mechanism. It provides following core components which can be injected into each other as dependencies. - value - factory - service - provider - constant

Q. - How angular.module works?

Ans. - angular.module is used to create AngularJS modules along with its dependent modules.

Q. - How to validate data in Angular4/5?

Ans. - AngularJS enriches form filling and validation. We can use $dirty and $invalid flags to do the validations in seamless way. Use novalidate with a form declaration to disable any browser specific validation. Following can be used to track error. - $dirty − states that value has been changed. - $invalid − states that value entered is invalid. - $error − states the exact error.

Q. - How to make an ajax call using Angular 4/5?

Ans. - AngularJS provides $http control which works as a service to make ajax call to read data from the server. The server makes a database call to get the desired records. AngularJS needs data in JSON format. Once the data is ready, $http can be used to get the data from server.

Q. - What is use of $routeProvider in Angular4/5?

Ans. - $routeProvider is the key service which set the configuration of urls, maps them with the corresponding html page or ng-template, and attaches a controller with the same.

Q. - What is scope hierarchy in Angular4/5?

Ans. - Scopes are controller specific. If we define nested controllers then child controller will inherit the scope of its parent controller.

Q. - Explain ng-include directive

Ans. - Using AngularJS, we can embed HTML pages within a HTML page using ng-include directive.

Q. - What is provider?

Ans. - Provider is used by AngularJS internally to create services, factory etc. during config phase(phase during which AngularJS bootstraps itself). Below mention script can be used to create MathService that we've created earlier. Provider is a special factory method with a method get() which is used to return the value/service/factory. var mainApp = angular.module(\, []); mainApp.config(function($provide) { \t $provide.provider('MathService', function() { \t this.$get = function() { \t var factory = {}; \t factory.multiply = function(a, b) { \t return a * b; \t } \t return factory; \t }; }); });

Q. - What is constant?

Ans. - Constants are used to pass values at config phase considering the fact that value cannot be used to be passed during config phase. mainApp.constant(\, \constant value\

Q. - On which types of component can we create a custom directive?

Ans. - AngularJS provides support to create custom directives for following type of elements. - Element directives − Directive activates when a matching element is encountered. - Attribute − Directive activates when a matching attribute is encountered. - CSS − Directive activates when a matching css style is encountered. - Comment − Directive activates when a matching comment is encountered.

Q. - What is internationalization?

Ans. - Internationalization is a way to show locale specific information on a website. For example, display content of a website in English language in United States and in Danish in France.

Q. - How to implement internationalization in Angular4/5?

Ans. - AngularJS supports inbuilt internationalization for three types of filters currency, date and numbers. We only need to incorporate corresponding js according to locale of the country. By default it handles the locale of the browser. For example, to use Danish locale, use following script

Q. - Explain filter.

Ans. - Filter is used to filter the array to a subset of it based on provided criteria.

Q. - Explain uppercase filter.

Ans. - Uppercase filter converts a text to upper case text.

Q. - Have you ever worked on an Angular project ?

Ans. - Mention project and advantages of the same - Mention the concepts learned

Q. - What does 'jps' command do?

Ans. - It gives the status of the deamons which run Hadoop cluster. It gives the output mentioning the status of namenode, datanode , secondary namenode, Jobtracker and Task tracker.

Q. - How to restart Namenode?

Ans. - Step-1. Click on and then click on OR Step-2. Write sudo hdfs (press enter), su-hdfs (press enter), /etc/init.d/ha (press enter) and then /etc/init.d/hadoop-0.20-namenode start (press enter).

Q. - Which are the three modes in which Hadoop can be run?

Ans. - The three modes in which Hadoop can be run are −1. standalone (local) mode 2. Pseudo-distributed mode 3. Fully distributed mode

Q. - What does /etc /init.d do?

Ans. - /etc /init.d specifies where daemons (services) are placed or to see the status of these daemons. It is very LINUX specific, and nothing to do with Hadoop.

Q. - What if a Namenode has no data?

Ans. - It cannot be part of the Hadoop cluster.

Q. - What happens to job tracker when Namenode is down?

Ans. - When Namenode is down, your cluster is OFF, this is because Namenode is the single point of failure in HDFS.

Q. - What is Big Data?

Ans. - Big Data is nothing but an assortment of such a huge and complex data that it becomes very tedious to capture, store, process, retrieve and analyze it with the help of on-hand database management tools or traditional data processing techniques.

Q. - What are the four characteristics of Big Data?

Ans. - the three characteristics of Big Data are −1.Volume − Facebook generating 500+ terabytes of data per day. 2. Velocity − Analyzing 2 million records each day to identify the reason for losses. 3.Variety − images, audio, video, sensor data, log files, etc. Veracity: biases, noise and abnormality in data

Q. - How is analysis of Big Data useful for organizations?

Ans. - Effective analysis of Big Data provides a lot of business advantage as organizations will learn which areas to focus on and which areas are less important. Big data analysis provides some early key indicators that can prevent the company from a huge loss or help in grasping a great opportunity with open hands! A precise analysis of Big Data helps in decision making! For instance, nowadays people rely so much on Facebook and Twitter before buying any product or service. All thanks to the Big Data explosion.

Q. - Why do we need Hadoop?

Ans. - Everyday a large amount of unstructured data is getting dumped into our machines. The major challenge is not to store large data sets in our systems but to retrieve and analyze the big data in the organizations, that too data present in different machines at different locations. In this situation a necessity for Hadoop arises. Hadoop has the ability to analyze the data present in different machines at different locations very quickly and in a very cost effective way. It uses the concept of MapReduce which enables it to divide the query into small parts and process them in parallel. This is also known as parallel computing. The following link Why Hadoop gives a detailed explanation about why Hadoop is gaining so much popularity!

Q. - What is the basic difference between traditional RDBMS and Hadoop?

Ans. - Traditional RDBMS is used for transactional systems to report and archive the data, whereas Hadoop is an approach to store huge amount of data in the distributed file system and process it. RDBMS will be useful when you want to seek one record from Big data, whereas, Hadoop will be useful when you want Big data in one shot and perform analysis on that later

Q. - What is Fault Tolerance?

Ans. - Suppose you have a file stored in a system, and due to some technical problem that file gets destroyed. Then there is no chance of getting the data back present in that file. To avoid such situations, Hadoop has introduced the feature of fault tolerance in HDFS. In Hadoop, when we store a file, it automatically gets replicated at two other locations also. So even if one or two of the systems collapse, the file is still available on the third system.

Q. - Replication causes data redundancy, then why is it pursued in HDFS?

Ans. - HDFS works with commodity hardware (systems with average configurations) that has high chances of getting crashed any time. Thus, to make the entire system highly fault-tolerant, HDFS replicates and stores data in different places. Any data on HDFS gets stored at least 3 different locations. So, even if one of them is corrupted and the other is unavailable for some time for any reason, then data can be accessed from the third one. Hence, there is no chance of losing the data. This replication factor helps us to attain the feature of Hadoop called Fault Tolerant.

Q. - Since the data is replicated thrice in HDFS, does it mean that any calculation done on one node will also be replicated on the other two?

Ans. - No, calculations will be done only on the original data. The master node will know which node exactly has that particular data. In case, if one of the nodes is not responding, it is assumed to be failed. Only then, the required calculation will be done on the second replica.

Q. - What is a Namenode?

Ans. - Namenode is the master node on which job tracker runs and consists of the metadata. It maintains and manages the blocks which are present on the datanodes. It is a high-availability machine and single point of failure in HDFS.

Q. - Is Namenode also a commodity hardware?

Ans. - No. Namenode can never be commodity hardware because the entire HDFS rely on it. It is the single point of failure in HDFS. Namenode has to be a high-availability machine.

Q. - What is a Datanode?

Ans. - Datanodes are the slaves which are deployed on each machine and provide the actual storage. These are responsible for serving read and write requests for the clients.

Q. - Why do we use HDFS for applications having large data sets and not when there are lot of small files?

Ans. - HDFS is more suitable for large amount of data sets in a single file as compared to small amount of data spread across multiple files. This is because Namenode is a very expensive high performance system, so it is not prudent to occupy the space in the Namenode by unnecessary amount of metadata that is generated for multiple small files. So, when there is a large amount of data in a single file, name node will occupy less space. Hence for getting optimized performance, HDFS supports large data sets instead of multiple small files.

Q. - What is a job tracker?

Ans. - Job tracker is a daemon that runs on a namenode for submitting and tracking MapReduce jobs in Hadoop. It assigns the tasks to the different task tracker. In a Hadoop cluster, there will be only one job tracker but many task trackers. It is the single point of failure for Hadoop and MapReduce Service. If the job tracker goes down all the running jobs are halted. It receives heartbeat from task tracker based on which Job tracker decides whether the assigned task is completed or not.

Q. - What is a task tracker?

Ans. - Task tracker is also a daemon that runs on datanodes. Task Trackers manage the execution of individual tasks on slave node. When a client submits a job, the job tracker will initialize the job and divide the work and assign them to different task trackers to perform MapReduce tasks. While performing this action, the task tracker will be simultaneously communicating with job tracker by sending heartbeat. If the job tracker does not receive heartbeat from task tracker within specified time, then it will assume that task tracker has crashed and assign that task to another task tracker in the cluster.

Q. - What is a heartbeat in HDFS?

Ans. - A heartbeat is a signal indicating that it is alive. A datanode sends heartbeat to Namenode and task tracker will send its heart beat to job tracker. If the Namenode or job tracker does not receive heart beat then they will decide that there is some problem in datanode or task tracker is unable to perform the assigned task.

Q. - What is a 'block' in HDFS?

Ans. - A 'block' is the minimum amount of data that can be read or written. In HDFS, the default block size is 64 MB as contrast to the block size of 8192 bytes in Unix/Linux. Files in HDFS are broken down into block-sized chunks, which are stored as independent units. HDFS blocks are large as compared to disk blocks, particularly to minimize the cost of seeks. If a particular file is 50 mb, will the HDFS block still consume 64 mb as the default size? No, not at all! 64 mb is just a unit where the data will be stored. In this particular situation, only 50 mb will be consumed by an HDFS block and 14 mb will be free to store something else. It is the MasterNode that does data allocation in an efficient manner.

Q. - What are the benefits of block transfer?

Ans. - A file can be larger than any single disk in the network. There's nothing that requires the blocks from a file to be stored on the same disk, so they can take advantage of any of the disks in the cluster. Making the unit of abstraction a block rather than a file simplifies the storage subsystem. Blocks provide fault tolerance and availability. To insure against corrupted blocks and disk and machine failure, each block is replicated to a small number of physically separate machines (typically three). If a block becomes unavailable, a copy can be read from another location in a way that is transparent to the client?

Q. - How indexing is done in HDFS?

Ans. - Hadoop has its own way of indexing. Depending upon the block size, once the data is stored, HDFS will keep on storing the last part of the data which will say where the next part of the data will be.

Q. - Are job tracker and task trackers present in separate machines?

Ans. - Yes, job tracker and task tracker are present in different machines. The reason is job tracker is a single point of failure for the Hadoop MapReduce service. If it goes down, all running jobs are halted.

Q. - What is the communication channel between client and namenode/datanode?

Ans. - The mode of communication is SSH.

Q. - What is a rack?

Ans. - Rack is a storage area with all the datanodes put together. These datanodes can be physically located at different places. Rack is a physical collection of datanodes which are stored at a single location. There can be multiple racks in a single location.

Q. - What is a Secondary Namenode? Is it a substitute to the Namenode?

Ans. - The secondary Namenode constantly reads the data from the RAM of the Namenode and writes it into the hard disk or the file system. It is not a substitute to the Namenode, so if the Namenode fails, the entire Hadoop system goes down.

Q. - Explain how do 'map' and 'reduce' works.

Ans. - Namenode takes the input and divide it into parts and assign them to data nodes. These datanodes process the tasks assigned to them and make a key-value pair and returns the intermediate output to the Reducer. The reducer collects this key value pairs of all the datanodes and combines them and generates the final output.

Q. - Why 'Reading' is done in parallel and 'Writing' is not in HDFS?

Ans. - Through mapreduce program the file can be read by splitting its blocks when reading. But while writing as the incoming values are not yet known to the system mapreduce cannot be applied and no parallel writing is possible.

Q. - Copy a directory from one node in the cluster to another

Ans. - Use '-distcp' command to copy,

Q. - Default replication factor to a file is 3.Use '-setrep' command to change replication factor of a file to 2.

Ans. - hadoop fs -setrep -w 2 apache_hadoop/sample.txt

Q. - What is rack awareness?

Ans. - Rack awareness is the way in which the namenode decides how to place blocks based on the rack definitions Hadoop will try to minimize the network traffic between datanodes within the same rack and will only contact remote racks if it has to. The namenode is able to control this due to rack awareness.

Q. - Which file does the Hadoop-core configuration?

Ans. - core-default.xml

Q. - Is there a hdfs command to see available free space in hdfs

Ans. - hadoop dfsadmin -report

Q. - The requirement is to add a new data node to a running Hadoop cluster; how do I start services on just one data node?

Ans. - You do not need to shutdown and/or restart the entire cluster in this case.

Q. - First, add the new node's DNS name to the conf/slaves file on the master node.

Ans. - Then log in to the new slave node and execute − $ cd path/to/hadoop, $ bin/ start datanode, $ bin/ start tasktracker , then issuehadoop dfsadmin -refreshNodes and hadoop mradmin -refreshNodes so that the NameNode and JobTracker know of the additional node that has been added.

Q. - How do you gracefully stop a running job?

Ans. - Hadoop job –kill jobid

Q. - Does the name-node stay in safe mode till all under-replicated files are fully replicated?

Ans. - No. During safe mode replication of blocks is prohibited. The name-node awaits when all or majority of data-nodes report their blocks.

Q. - What happens if one Hadoop client renames a file or a directory containing this file while another client is still writing into it?

Ans. - A file will appear in the name space as soon as it is created. If a writer is writing to a file and another client renames either the file itself or any of its path components, then the original writer will get an IOException either when it finishes writing to the current block or when it closes the file.

Q. - How to make a large cluster smaller by taking out some of the nodes?

Ans. - Hadoop offers the decommission feature to retire a set of existing data-nodes. The nodes to be retired should be included into the exclude file, and the exclude file name should be specified as a configuration parameter dfs.hosts.exclude. The decommission process can be terminated at any time by editing the configuration or the exclude files and repeating the -refreshNodes command

Q. - Can we search for files using wildcards?

Ans. - Yes. For example, to list all the files which begin with the letter a, you could use the ls command with the * wildcard &minu; hdfs dfs –ls a*

Q. - What happens when two clients try to write into the same HDFS file?

Ans. - HDFS supports exclusive writes only. When the first client contacts the name-node to open the file for writing, the name-node grants a lease to the client to create this file. When the second client tries to open the same file for writing, the name-node will see that the lease for the file is already granted to another client, and will reject the open request for the second client

Q. - What does file could only be replicated to 0 nodes, instead of 1 mean?

Ans. - The namenode does not have any available DataNodes.

Q. - What is a Combiner?

Ans. - The Combiner is a 'mini-reduce' process which operates only on data generated by a mapper. The Combiner will receive as input all data emitted by the Mapper instances on a given node. The output from the Combiner is then sent to the Reducers, instead of the output from the Mappers

Q. - Consider case scenario: In M/R system, - HDFS block size is 64 MB - Input format is FileInputFormat – We have 3 files of size 64K, 65Mb and 127Mb How many input splits will be made by Hadoop framework?

Ans. - Hadoop will make 5 splits as follows − - 1 split for 64K files - 2 splits for 65MB files - 2 splits for 127MB files

Q. - Suppose Hadoop spawned 100 tasks for a job and one of the task failed. What will Hadoop do?

Ans. - It will restart the task again on some other TaskTracker and only if the task fails more than four ( the default setting and can be changed) times will it kill the job.

Q. - What are Problems with small files and HDFS?

Ans. - HDFS is not good at handling large number of small files. Because every file, directory and block in HDFS is represented as an object in the namenode's memory, each of which occupies approx 150 bytes So 10 million files, each using a block, would use about 3 gigabytes of memory. when we go for a billion files the memory requirement in namenode cannot be met.

Q. - What is speculative execution in Hadoop?

Ans. - If a node appears to be running slow, the master node can redundantly execute another instance of the same task and first output will be taken .this process is called as Speculative execution.

Q. - Can Hadoop handle streaming data?

Ans. - Yes, through Technologies like Apache Kafka, Apache Flume, and Apache Spark it is possible to do large-scale streaming.

Q. - Why is Checkpointing Important in Hadoop?

Ans. - As more and more files are added the namenode creates large edit logs. Which can substantially delay NameNode startup as the NameNode reapplies all the edits. Checkpointing is a process that takes an fsimage and edit log and compacts them into a new fsimage. This way, instead of replaying a potentially unbounded edit log, the NameNode can load the final in-memory state directly from the fsimage. This is a far more efficient operation and reduces NameNode startup time.

Q. - What is Twitter Bootstrap?

Ans. - Bootstrap is a sleek, intuitive, and powerful mobile first front-end framework for faster and easier web development. It uses HTML, CSS and Javascript.

Q. - Why use Bootstrap?

Ans. - Bootstrap can be used as − Mobile first approach − Since Bootstrap 3, the framework consists of Mobile first styles throughout the entire library instead of in separate files. Browser Support − It is supported by all popular browsers. Easy to get started − With just the knowledge of HTML and CSS anyone can get started with Bootstrap. Also the Bootstrap official site has a good documentation. Responsive design − Bootstrap's responsive CSS adjusts to Desktops,Tablets and Mobiles. Provides a clean and uniform solution for building an interface for developers. It contains beautiful and functional built-in components which are easy to customize. It also provides web based customization. And best of all it is an open source.

Q. - What does Bootstrap package includes?

Ans. - Bootstrap package includes −Scaffolding − Bootstrap provides a basic structure with Grid System, link styles, background. This is is covered in detail in the section Bootstrap Basic Structure CSS − Bootstrap comes with feature of global CSS settings, fundamental HTML elements styled and enhanced with extensible classes, and an advanced grid system. This is covered in detail in the section Bootstrap with CSS. Components − Bootstrap contains over a dozen reusable components built to provide iconography, dropdowns, navigation, alerts, popovers, and much more. This is covered in detail in the section Layout Components. JavaScript Plugins − Bootstrap contains over a dozen custom jQuery plugins. You can easily include them all, or one by one. This is covered in details in the section Bootstrap Plugins. Customize − You can customize Bootstrap's components, LESS variables, and jQuery plugins to get your very own version.

Q. - What is Contextual classes of table in Bootstrap?

Ans. - The Contextual classes allow you to change the background color of your table rows or individual cells.

Q. -

Ans. - Class Description

Q. -

Ans. - .active Applies the hover color to a particular row or cell

Q. -

Ans. - .success Indicates a successful or positive action

Q. -

Ans. - .warning Indicates a warning that might need attention

Q. -

Ans. - .danger Indicates a dangerous or potentially negative action

Q. - What is Bootstrap Grid System?

Ans. - Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases. It includes predefined classes for easy layout options, as well as powerful mixins for generating more semantic layouts.

Q. - What are Bootstrap media queries?

Ans. - Media Queries in Bootstrap allow you to move, show and hide content based on viewport size.

Q. - What are Offset columns?

Ans. - Offsets are a useful feature for more specialized layouts. They can be used to push columns over for more spacing, for example. The .col-xs=* classes don't support offsets, but they are easily replicated by using an empty cell.

Q. - How can you order columns in Bootstrap?

Ans. - You can easily change the order of built-in grid columns with .col-md-push-* and .col-md-pull-* modifier classes where * range from 1 to 11.

Q. - How do you make images responsive?

Ans. - Bootstrap 3 allows to make the images responsive by adding a class .img-responsive to the tag. This class applies max-width: 100%; and height: auto; to the image so that it scales nicely to the parent element.

Q. - Explain the typography and links in Bootstrap.

Ans. - Bootstrap sets a basic global display (background), typography, and link styles − Basic Global display − Sets background-color: #fff; on the element. Typography − Uses the @font-family-base, @font-size-base, and @line-height-base attributes as the typographic base Link styles − Sets the global link color via attribute @link-color and apply link underlines only on :hover.

Q. - What is Normalize in Bootstrap?

Ans. - Bootstrap uses Normalize to establish cross browser consistency. Normalize.css is a modern, HTML5-ready alternative to CSS resets. It is a small CSS file that provides better cross-browser consistency in the default styling of HTML elements.

Q. - What is Lead Body Copy

Ans. - To add some emphasis to a paragraph, add class=lead. This will give you larger font size, lighter weight, and a taller line height

Q. - Explain types of lists supported by Bootstrap.

Ans. - Bootstrap supports ordered lists, unordered lists, and definition lists. Ordered lists − An ordered list is a list that falls in some sort of sequential order and is prefaced by numbers. Unordered lists − An unordered list is a list that doesn't have any particular order and is traditionally styled with bullets. If you do not want the bullets to appear then you can remove the styling by using the class .list-unstyled. You can also place all list items on a single line using the class .list-inline. Definition lists − In this type of list, each list item can consist of both the

and the
stands for definition term, and like a dictionary, this is the term (or phrase) that is being defined. Subsequently, the
is the definition of the
. You can make terms and descriptions in
line up side-by-side using class dl-horizontal.

Q. - What are glyphicons?

Ans. - Glyphicons are icon fonts which you can use in your web projects. Glyphicons Halflings are not free and require licensing, however their creator has made them available for Bootstrap projects free of cost.

Q. - How do you use Glyphicons?

Ans. - To use the icons, simply use the following code just about anywhere in your code. Leave a space between the icon and text for proper padding.

Q. - What is a transition plugin?

Ans. - The transition plugin provides simple transition effects such as Sliding or fading in modals.

Q. - What is a Modal Plugin?

Ans. - A modal is a child window that is layered over its parent window. Typically, the purpose is to display content from a separate source that can have some interaction without leaving the parent window. Child windows can provide information, interaction, or more.

Q. - What is Bootstrap caraousel?

Ans. - The Bootstrap carousel is a flexible, responsive way to add a slider to your site. In addition to being responsive, the content is flexible enough to allow images, iframes, videos, or just about any type of content that you might want.

Q. - What is button group

Ans. - Button groups allow multiple buttons to be stacked together on a single line. This is useful when you want to place items like alignment buttons together.

Q. - Which class is used for basic button group

Ans. - .btn-group class is used for a basic button group. Wrap a series of buttons with class .btn in .btn-group.

Q. - Which class is used to draw a toolbar of buttons

Ans. - .btn-toolbar helps to combine sets of

into a
for more complex components.

Q. - Which classses can be applied to button group instead of resizing each button

Ans. - .btn-group-lg, .btn-group-sm, .btn-group-xs classses can be applied to button group instead of resizing each button.

Q. - Which class make a set of buttons appear vertically stacked rather than horizontally

Ans. - .btn-group-vertical class make a set of buttons appear vertically stacked rather than horizontally.

Q. - What are input groups

Ans. - Input groups are extended Form Controls. Using input groups you can easily prepend and append text or buttons to the text-based inputs. By adding prepended and appended content to an input field, you can add common elements to the user's input. For example, you can add the dollar symbol, the @ for a Twitter username, or anything else that might be common for your application interface. To prepend or append elements to a .form-control − Wrap it in a

with class .input-group As a next step, within that same
, place your extra content inside a with class .input-group-addon. Now place this either before or after the element.

Q. - How will you create a tabbed navigation menu

Ans. - To create a tabbed navigation menu − Start with a basic unordered list with the base class of .nav. Add class .nav-tabs.

Q. - How will you create a pills navigation menu

Ans. - To create a pills navigation menu − Start with a basic unordered list with the base class of .nav. Add class .nav-pills.

Q. - How will you create a vertical pills navigation menu

Ans. - You can stack the pills vertically using the class .nav-stacked along with the classes: .nav, .nav-pills.

Q. - What is bootstrap navbar

Ans. - The navbar is one of the prominent features of Bootstrap sites. Navbars are responsive 'meta' components that serve as navigation headers for your application or site. Navbars collapse in mobile views and become horizontal as the available viewport width increases. At its core, the navbar includes styling for site names and basic navigation.

Q. - How to create a navbar in bootstrap

Ans. - To create a default navbar − Add the classes .navbar, .navbar-default to the

Q. - What is bootstrap breadcrumb

Ans. - Breadcrumbs are a great way to show hierarchy-based information for a site. In the case of blogs, breadcrumbs can show the dates of publishing, categories, or tags. They indicate the current page's location within a navigational hierarchy.

A breadcrumb in Bootstrap is simply an unordered list with a class of .breadcrumb. The separator is automatically added by CSS (bootstrap.min.css).

Q. - Which class is used for basic pagination

Ans. - .pagination class is uesed to add the pagination on a page.

Q. - How will you customize links of pagination

Ans. - You can customize links by using .disabled for unclickable links and .active to indicate the current page.

Q. - What are bootstrap labels

Ans. - Bootstrap labels are great for offering counts, tips, or other markup for pages. Use class .label to display labels.

Q. - What are bootstrap badges

Ans. - Badges are similar to labels; the primary difference is that the corners are more rounded. Badges are mainly used to highlight new or unread items. To use badges just add to links, Bootstrap navs, and more.

Q. - What is Bootstrap Jumbotron

Ans. - As the name suggest this component can optionally increase the size of headings and add a lot of margin for landing page content. To use the Jumbotron − Create a container

with the class of .jumbotron. In addition to a larger

, the font-weight is reduced to 200px.

Q. - What is Bootstrap page header

Ans. - The page header is a nice little feature to add appropriate spacing around the headings on a page. This is particularly helpful on a web page where you may have several post titles and need a way to add distinction to each of them. To use a page header, wrap your heading in a

with a class of .page-header.

Q. - How to create thumbnails using Bootstrap

Ans. - To create thumbnails using Bootstrap − Add an tag with the class of .thumbnail around an image. This adds four pixels of padding and a gray border. On hover, an animated glow outlines the image.

Q. - What are bootstrap alerts?

Ans. - Bootstrap Alerts provide a way to style messages to the user. They provide contextual feedback messages for typical user actions. You can add an optional close icon to alert.

Q. - How will you create a bootstrap alert?

Ans. - You can add a basic alert by creating a wrapper

and adding a class of .alert and one of the four contextual classes (e.g., .alert-success, .alert-info, .alert-warning, .alert-danger).

Q. - How will you create a Bootstrap Dismissal Alert?

Ans. - To build a dismissal alert − Add a basic alert by creating a wrapper

and adding a class of .alert and one of the four contextual classes (e.g., .alert-success, .alert-info, .alert-warning, .alert-danger). Also add optional .alert-dismissable to the above
class. Add a close button. Use the
Q. - How will you create a progress bar using bootstrap?

Ans. - To create a basic progress bar − Add a

with a class of .progress. Next, inside the above
, add an empty
with a class of .progress-bar. Add a style attribute with the width expressed as a percentage. Say for example, style=60%; indicates that the progress bar was at 60%.

Q. - How will you create a alternate progress bar using bootstrap?

Ans. - To create a progress bar with different styles − Add a

with a class of .progress. Next, inside the above
, add an empty
with a class of .progress-bar and class progress-bar-* where * could be success, info, warning, danger. Add a style attribute with the width expressed as a percentage. Say for example, style=60%; indicates that the progress bar was at 60%.

Q. - How will you create a striped progress bar using bootstrap

Ans. - o create a striped progress bar − Add a

with a class of .progress and .progress-striped. Next, inside the above
, add an empty
with a class of .progress-bar and class progress-bar-* where * could be success, info, warning, danger. Add a style attribute with the width expressed as a percentage. Say for example, style=60%; indicates that the progress bar was at 60%.

Q. - How will you create a animated progress bar using bootstrap?

Ans. - To create an animated progress bar − Add a

with a class of .progress and .progress-striped. Also add class .active to .progress-striped. Next, inside the above
, add an empty
with a class of .progress-bar. Add a style attribute with the width expressed as a percentage. Say for example, style=60%; indicates that the progress bar was at 60%.

Q. - How will you create a stacked progress bar using bootstrap

Ans. - You can even stack multiple progress bars. Place the multiple progress bars into the same .progress to stack them.

Q. - What are bootstrap media objects

Ans. - These are abstract object styles for building various types of components (like blog comments, Tweets, etc.) that feature a left-aligned or right-aligned image alongside the textual content. The goal of the media object is to make the code for developing these blocks of information drastically shorter. The goal of media objects (light markup, easy extendability) is achieved by applying classes to some of the simple markup.

Q. - What is the purpose of .mecia class in bootstrap?

Ans. - This class allows to float a media object (images, video, and audio) to the left or right of a content block.

Q. - What is the purpose of .media-list class in bootstrap

Ans. - If you are preparing a list where the items will be part of an unordered list, use a class. useful for comment threads or articles lists.

Q. - What are bootstrap panels

Ans. - Panel components are used when you want to put your DOM component in a box. To get a basic panel, just add class .panel to the

element. Also add class .panel-default to this element.

Q. - How will you create a bootstrap panel with heading

Ans. - here are two ways to add panel heading − Use .panel-heading class to easily add a heading container to your panel. Use any


with a .panel-title class to add a pre-styled heading.

Q. - How will you create a bootstrap panel with footer

Ans. - You can add footers to panels, by wrapping buttons or secondary text in a

containing class .panel-footer.

Q. - What contextual classes are available to style the panels

Ans. - Use contextual state classes such as, panel-primary, panel-success, panel-info, panel-warning, panel-danger, to make a panel more meaningful to a particular context.

Q. - Can you put a table within bootstrap panel

Ans. - Yes! To get a non-bordered table within a panel, use the class .table within the panel. Suppose there is a

containing .panel-body, we add an extra border to the top of the table for separation. If there is no
containing .panel-body, then the component moves from panel header to table without interruption.

Q. - Can you put a listgroup within bootstrap panel

Ans. - Yes! You can include list groups within any panel. Create a panel by adding class .panel to the

element. Also add class .panel-default to this element. Now within this panel include your list groups.

Q. - What is bootstrap well

Ans. - A well is a container in

that causes the content to appear sunken or an inset effect on the page. To create a well, simply wrap the content that you would like to appear in the well with a
containing the class of .well.

Q. - What is Scrollspy plugin

Ans. - The Scrollspy (auto updating nav) plugin allows you to target sections of the page based on the scroll position. In its basic implementation, as you scroll, you can add .active classes to the navbar based on the scroll position.

Q. - What is affix plugin

Ans. - The affix plugin allows a

to become affixed to a location on the page. You can also toggle it's pinning on and off using this plugin. A common example of this are social icons. They will start in a location, but as the page hits a certain mark, the
will be locked in place and will stop scrolling with the rest of the page.

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