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Java Interview Questions
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All Java Questions
Java medium
Base class for Error and Exceptions?
Topic: General
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Java medium
Break statement can be used as labels in Java?
Topic: General
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Java medium
Can a class declared as private be accessed outside it's package?
Topic: General
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Java medium
Can a class extend an interface?
Topic: General
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Java medium
Can a constructor be made final?
Topic: General
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Java medium
Can a double value be cast to a byte?
Topic: General
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Java medium
Can a local class declared inside a static method have access to the instance members of the outer class?
Topic: General
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Java medium
Can a method local inner class access the local final variables?Why?
Topic: General
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Java medium
Can a static nested class have access to the enclosing class non-static methods or instance variables?
Topic: General
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Java medium
Can a top level class be private or protected?
Topic: General
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Java medium
Can Abstract methods in parent class have a body?
Topic: General
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Java medium
Can an abstract class have a constructor?
Topic: General
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Java medium
Can an abstract class have a static method?
Topic: General
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Java medium
Can an anonymous class define method of its own?
Topic: General
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Java medium
Can an anonymous class implement an interface and also extend a class at the same time?
Topic: General
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Java medium
Can an exception be rethrown?
Topic: General
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Java medium
Can an interface be final?
Topic: General
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Java medium
Can an Interface extend another Interface?
Topic: General
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Java medium
Can an unreferenced object be referenced again?
Topic: General
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Java medium
Can constructor be inherited?
Topic: General
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Java medium
Can finally block be used without catch?
Topic: General
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Java medium
Can i import same package/class twice?
Topic: General
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Java medium
Can overloaded methods be override too?
Topic: General
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Java medium
Can static block throw exception?
Topic: General
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Java medium
Can the method local inner class object access method's local variables?
Topic: General
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Java medium
Can there be an abstract class with no abstract methods in it?
Topic: General
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Java medium
Can this keyword be assigned null value?
Topic: General
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Java medium
Can try statements be nested?
Topic: General
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Java medium
Can we achieve runtime polymorphism by data members?
Topic: General
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Java medium
Can we create an object for an interface?
Topic: General
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Java medium
Can we declare a class static?
Topic: General
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Java medium
Can we declare an abstract method private?
Topic: General
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Java medium
Can we declare an interface method static?
Topic: General
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Java medium
Can we declare interface method's private?
Topic: General
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Java medium
Can we declare interface methods as private?
Topic: General
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Java medium
Can we declare main method as final?
Topic: General
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Java medium
Can we have abstract methods in a class which is not Abstract?
Topic: General
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Java medium
Can we have an abstract class without abstract methods?
Topic: General
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Java medium
Can we have the try block without catch block?
Topic: General
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Java medium
Can we instantiate an abstract class?
Topic: General
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Java medium
Can we instantiate an interface?
Topic: General
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Java medium
Can we instantiate the object of derived class if parent constructor is protected?
Topic: General
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Java medium
Can we make an object final i.e immutable using final keyword?
Topic: General
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Java medium
Can we make constructor final?
Topic: General
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Java medium
Can we overload constructors?
Topic: General
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Java medium
Can we overload main method?
Topic: General
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Java medium
Can we override main method?
Topic: General
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Java medium
Can we override static methods?
Topic: General
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Java medium
Can we put more than one main class in a single java file?
Topic: General
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Java medium
Can we put more than one main method in single class?
Topic: General
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Java medium
Can we put more than one public class in single java file?
Topic: General
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Java medium
Can we reduce the visibility of the "overridden" method?
Topic: General
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Java medium
Can we use both "this" and "super" in a constructor?
Topic: General
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Java medium
Can you call one constructor from another if a class has multiple constructors?
Topic: General
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Java medium
Define class?
Topic: General
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Java medium
Define composition?
Topic: General
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Java medium
Define JIT compiler?
Topic: General
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Java medium
Define Packages in Java?
Topic: General
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Java medium
Difference between Abstract and Concrete Class?
Topic: General
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Java medium
Difference between boolean and Boolean?
Topic: General
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Java medium
Difference between C++ and Java?
Topic: General
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Java medium
Difference between class and objects?
Topic: General
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Java medium
Difference between implicit and explicit type casting?
Topic: General
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Java medium
Difference between loadClass and Class.forName?
Topic: General
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Java medium
Difference between Overloading and Overriding?
Topic: General
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Java medium
Difference between Private , Public and Protected?
Topic: General
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Java medium
Difference between protected and default Modifier?
Topic: General
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Java medium
Difference between serializable and externalizable interface?
Topic: General
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Java medium
Different types of memory used by JVM?
Topic: General
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Java medium
Do interfaces have member variables?
Topic: General
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Java medium
Does all property of immutable object needs to be final?
Topic: General
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Java medium
Does constructor returns any value?
Topic: General
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Java medium
Does it matter in what order catch statements for FileNotFoundException and IOException are written?
Topic: General
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Java medium
Does Java support multiple inheritence?
Topic: General
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Java medium
Explain Autoboxing?
Topic: General
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Java medium
Explain java.lang.OutOfMemoryError?
Topic: General
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Java medium
Explain the different forms of Polymorphism.
Topic: General
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Java medium
Explain the import keyword.
Topic: General
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Java medium
Explain the usage of this() with constructors?
Topic: General
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Java medium
Explain the use of "Native" keyword?
Topic: General
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Java medium
Explain the working of JVM.
Topic: General
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Java medium
Give a brief history of Java.
Topic: General
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Java medium
Give an example of immutable class?
Topic: General
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Java medium
How are this() and super() used with constructors?
Topic: General
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Java medium
How can we make sure that a code segment gets executed even in case of uncatched exceptions?
Topic: General
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Java medium
How can we make the object immutable?
Topic: General
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Java medium
How do you prevent a method from being overridden?
Topic: General
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Java medium
How does Java implement polymorphism?
Topic: General
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Java medium
How does the Java default constructor be provided?
Topic: General
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Java medium
How is java platform independent?
Topic: General
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Java medium
How Java enabled High Performance?
Topic: General
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Java medium
How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?
Topic: General
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Java medium
How to create custom exceptions?
Topic: General
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Java medium
How to invoke a superclass version of an Overridden method?
Topic: General
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Java medium
If a method is declared as protected, where may the method be accessed?
Topic: General
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Java medium
If a variable is declared as private, where may the variable be accessed?
Topic: General
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Java medium
If System.exit (0); is written at the end of the try block, will the finally block still execute?
Topic: General
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Java medium
If you compile a file containing inner class how many .class files are created and what are all of them accessible in usual way?
Topic: General
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Java medium
Is constructor inherited?
Topic: General
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Java medium
Is it necessary that each try block must be followed by a catch block?
Topic: General
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Java medium
Is Java Compiled or an Interpreted language?
Topic: General
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Java medium
Is Java purely Object Oriented? Explain.
Topic: General
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Java medium
Is JVM, a compiler or interpretor?
Topic: General
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Java medium
Is main a keyword in Java?
Topic: General
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Java medium
Is that the only way to initialize the object in that case?
Topic: General
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Java medium
Is there any limitation of using Inheritance?
Topic: General
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Java medium
Is there any need to import java.lang package?
Topic: General
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Java medium
List any five features of Java?
Topic: General
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Java medium
List primitive Java types?
Topic: General
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Java medium
List the three steps for creating an Object for a class?
Topic: General
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Java medium
List two Java IDE's?
Topic: General
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Java medium
Name few Java marker interfaces?
Topic: General
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Java medium
Name Wrapper classes available for primitive types?
Topic: General
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Java medium
Property Class?
Topic: General
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Java medium
runnable a Marker interface?
Topic: General
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Java medium
Variable of the boolean type is automatically initialized as?
Topic: General
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Java medium
What are disadvantages of using inner classes?
Topic: General
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Java medium
What are packages?
Topic: General
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Java medium
What are the advantages of Inner classes?
Topic: General
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Java medium
What are the advantages of using exception handling?
Topic: General
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Java medium
What are the design considerations while making a choice between using interface and abstract class?
Topic: General
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Java medium
What are the different class loaders used by JVM?
Topic: General
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Java medium
What are the different types of inner classes?
Topic: General
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Java medium
What are the different ways to handle exceptions?
Topic: General
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Java medium
What are the principle concepts of OOPS?
Topic: General
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Java medium
What are the types of Exceptions in Java
Topic: General
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Java medium
What are wrapper classes?
Topic: General
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Java medium
What class of exceptions are generated by the Java run-time system?
Topic: General
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Java medium
What Design pattern Wrapper Classes implement?
Topic: General
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Java medium
What do you mean by Access Modifier?
Topic: General
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Java medium
What do you mean by object?
Topic: General
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Java medium
What do you mean by return type Void?
Topic: General
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Java medium
What environment variables do I need to set on my machine in order to be able to run Java programs?
Topic: General
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Java medium
What if there is a break or return statement in try block followed by finally block?
Topic: General
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Java medium
What is a class file?
Topic: General
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Java medium
What is a Class Loader?
Topic: General
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Java medium
What is a Class Variable
Topic: General
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Java medium
What is a Final variable?
Topic: General
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Java medium
What is a Instance Variable
Topic: General
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Java medium
What is a Local Variable
Topic: General
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Java medium
What is a marker interface?
Topic: General
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Java medium
What is a nested interface?
Topic: General
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Java medium
What is a Static import?
Topic: General
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Java medium
What is a strictfp modifier?
Topic: General
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Java medium
What is a transient variable?
Topic: General
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Java medium
What is a WAR file?
Topic: General
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Java medium
What is Abstraction?
Topic: General
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Java medium
What is an abstract class?
Topic: General
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Java medium
What is an exception?
Topic: General
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Java medium
What is an Externalizable interface?
Topic: General
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Java medium
What is an Immutable object?
Topic: General
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Java medium
What is an inner class?
Topic: General
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Java medium
What is an Interface?
Topic: General
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Java medium
What is an Object class?
Topic: General
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Java medium
What is assert keyword used for?
Topic: General
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Java medium
What is Constructor?
Topic: General
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Java medium
What is constructor chaining and how is it achieved in Java?
Topic: General
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Java medium
What is Default Access?
Topic: General
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Java medium
What is difference between abstract class and interface?
Topic: General
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Java medium
What is difference between instanceof and isInstance(Object obj)?
Topic: General
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Java medium
What is difference between Path and Classpath?
Topic: General
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Java medium
What is dot operator?
Topic: General
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Java medium
What is Downcasting?
Topic: General
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Java medium
What is Encapsulation?
Topic: General
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Java medium
What is error?
Topic: General
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Java medium
What is exception propogation?
Topic: General
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Java medium
What is Externalizable interface?
Topic: General
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Java medium
What is final class?
Topic: General
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Java medium
What is final keyword?
Topic: General
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Java medium
What is immutable object? Can you write immutable object?
Topic: General
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Java medium
What is "Import" used for?
Topic: General
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Java medium
What is Inheritance?
Topic: General
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Java medium
What is JAR file?
Topic: General
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Java medium
What is Java Byte Code?
Topic: General
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Java medium
What is JDK?
Topic: General
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Java medium
What is JRE?
Topic: General
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Java medium
What is JVM?
Topic: General
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Java medium
What is keyword instanceOf used for?
Topic: General
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Java medium
What is Locale?
Topic: General
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Java medium
What is method overloading?
Topic: General
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Java medium
What is method overriding?
Topic: General
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Java medium
What is NullPointerException?
Topic: General
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Java medium
What is Polymorphism?
Topic: General
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Java medium
What is protected access modifier?
Topic: General
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Java medium
What is reflection?
Topic: General
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Java medium
What is runtime polymorphism or dynamic method dispatch?
Topic: General
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Java medium
What is static block?
Topic: General
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Java medium
What is static class?
Topic: General
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Java medium
What is "super" used for?
Topic: General
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Java medium
What is the default value for Object Reference in Java?
Topic: General
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Java medium
What is the default value of an object reference declared as an instance variable?
Topic: General
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Java medium
What is the default value of byte datatype in Java?
Topic: General
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Java medium
What is the default value of float and double datatype in Java?
Topic: General
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Java medium
What is the default value of local variable?
Topic: General
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Java medium
What is the difference between a break statement and a continue statement?
Topic: General
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Java medium
What is the difference between abstraction and encapsulation?
Topic: General
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Java medium
What is the difference between error and an exception?
Topic: General
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Java medium
What is the difference between object oriented programming language and object based programming language?
Topic: General
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Java medium
What is the difference between static and instance methods?
Topic: General
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Java medium
What is the difference throw and throws?
Topic: General
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Java medium
What is the GregorianCalendar class?
Topic: General
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Java medium
What is the Locale class?
Topic: General
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Java medium
What is the primary benefit of Encapsulation?
Topic: General
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Java medium
What is the purpose of default constructor?
Topic: General
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Java medium
What is the purpose of making an object immutable?
Topic: General
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Java medium
What is the purpose of System Class?
Topic: General
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Java medium
What is the range of the short type?
Topic: General
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Java medium
What is the relation between class file and byte code?
Topic: General
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Java medium
What is the SimpleTimeZone class?
Topic: General
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Java medium
What is the use of finally block?
Topic: General
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Java medium
What is the use of Marker interface if they don't hold anything?
Topic: General
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Java medium
What is the use of Volatile Keyword?
Topic: General
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Java medium
What is "this" keyword used for?
Topic: General
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Java medium
What is type casting?
Topic: General
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Java medium
What is volatile keyword?
Topic: General
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Java medium
What kind of variables a class can consist of?
Topic: General
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Java medium
What modifiers are allowed for methods in an Interface?
Topic: General
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Java medium
What restrictions are placed on method overriding?
Topic: General
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Java medium
What's the difference between constructors and other methods?
Topic: General
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Java medium
What will happen if static modifier is removed from the signature of the main method?
Topic: General
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Java medium
What will happen if we declare a class abstract as well as final?
Topic: General
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Java medium
What will happen if we make the constructor private?
Topic: General
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Java medium
When a byte datatype is used?
Topic: General
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Java medium
When Abstract methods are used?
Topic: General
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Java medium
When ArithmeticException is thrown?
Topic: General
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Java medium
When is the ArrayStoreException thrown?
Topic: General
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Java medium
When parseInt() method can be used?
Topic: General
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Java medium
When should I use abstract classes and when should I use interfaces?
Topic: General
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Java medium
When super keyword is used?
Topic: General
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Java medium
When you declare a method as abstract, can other nonabstract methods access it?
Topic: General
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Java medium
Where and how can you use a private constructor?
Topic: General
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Java medium
Which are the two subclasses under Exception class?
Topic: General
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Java medium
Which arithmetic operations can result in the throwing of an ArithmeticException?
Topic: General
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Java medium
Which is superclass of Exception?
Topic: General
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Java medium
Which is the super class of all classes in java?
Topic: General
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Java medium
Which modifiers can be applied to the method local inner class?
Topic: General
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Java medium
Which object oriented Concept is achieved by using overloading and overriding?
Topic: General
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Java medium
Who calls the main method in java?
Topic: General
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Java medium
Why do member variables have default values whereas local variables don't have any default value?
Topic: General
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Java medium
Why Errors are Not Checked?
Topic: General
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Java medium
Why inner class can access only final variable?
Topic: General
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Java medium
Why is char 2 bytes?
Topic: General
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Java medium
Why Java don't use pointers?
Topic: General
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Java medium
Why Java is considered dynamic?
Topic: General
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Java medium
Why Packages are used?
Topic: General
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Java medium
Why Runtime Exceptions are Not Checked?
Topic: General
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Java medium
Why static methods cannot access non static variables or methods?
Topic: General
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