Java Operators

Java Control Statements

Object Oriented Programming

Java Built-in Classes

Java File Handling

Java Error & Exceptions

Java Multithreading

Java Synchronization

Java Networking

Java Collections

Java Interfaces

Java Data Structures

Java Collections Algorithms

Advanced Java

Java Miscellaneous

Java APIs & Frameworks

Java Class References

Java Useful Resources

Java Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Core Java. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - What is the size of byte variable?

Answer : A

Explaination

The byte data type is represented by an 8-bit signed two's complement integer.

Minimum value: -128

Maximum value: 127

Q 2 - What is the size of float variable?

Answer : C

Explaination

The float data type is represented by single-precision 32-bit IEEE 754 floating point.

Q 3 - What is the default value of short variable?

Answer : B

Explaination

Short variable has default value of 0 if defined as an instance/static variable.

Q 4 - Which of the following is true about public access modifier?

A - Variables, methods and constructors which are declared public can be accessed by any class.

B - Variables, methods and constructors which are declared public can be accessed by any class lying in same package.

C - Variables, methods and constructors which are declared public in the superclass can be accessed only by its child class.

D - None of the above.

Answer : A

Explaination

Public access modifier is used to make variables, methods and constructors accessible to any class.

Q 5 - What is Encapsulation?

A - Encapsulation is a technique to define different methods of same type.

B - Encapsulation is the ability of an object to take on many forms.

C - Encapsulation is the technique of making the fields in a class private and providing access to the fields via public methods.

D - None of the above.

Answer : C

Explaination

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 6 - What is static block?

A - It is used to create syncronized code.

B - There is no such block.

C - It is used to initialize the static data member., It is excuted before main method at the time of class loading.

D - None of the above.

Answer : C

Explaination

static block is used to initialize the static data member.It is executed before main method at the time of loading of a class.

Q 7 - Method Overloading is an example of

A - Static Binding.

B - Dynamic Binding.

C - Both of the above.

D - None of the above.

Answer : A

Explaination

Method Overloading is example of static binding.

Q 8 - What is Serialization?

A - Serialization is the process of writing the state of an object to another object.

B - Serialization is the process of writing the state of an object to a byte stream.

C - Both of the above.

D - None of the above.

Answer : B

Explaination

Serialization is the process of writing the state of an object to a byte stream.

Q 9 - What is runtime polymorphism?

A - Runtime polymorphism is a process in which a call to an overridden method is resolved at runtime rather than at compile-time.

B - Runtime polymorphism is a process in which a call to an overloaded method is resolved at runtime rather than at compile-time.

C - Both of the above.

D - None of the above.

Answer : A

Explaination

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 10 - What is a marker interface?

A - marker interface is an interface with no method.

B - marker interface is an interface with single method, mark().

C - marker interface is an interface with single method, marker().

D - none of the above.

Answer : A

Explaination

Marker interface is an interface with no method.

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