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 - Static functions can be accessed using null reference.

A - True

B - False

Answer : A

Explaination

True, Static functions can be accessed via class name or via null reference.

Q 2 - Can we have two public classes in one java file?

A - True

B - False

Answer : B

Explaination

No, a java file can contain only one public class.

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

Answer : C

Explaination

String variable has default value of null if defined as an instance/static variable.

Q 4 - Which of the following is true about super class?

A - Variables, methods and constructors which are declared private can be accessed only by the members of the super class.

B - Variables, methods and constructors which are declared protected can be accessed by any subclass of the super class.

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

D - All of the above.

Answer : D

Explaination

All of the above are correct.

Q 5 - A class always has a default constructor.

A - True

B - False

Answer : B

Explaination

It is not mandatory to have a default constructor in a class.

Q 6 - Composition represents

A - HAS-A relationship.

B - IS-A relationship.

Answer : A

Explaination

Holding the reference of the other class within some other class is known as composition. It represents a HAS-A relationship. For example, a Student has a Pen. Here Student class has Pen as its instance variable.

Q 7 - What is function overriding?

A - If a subclass uses a method that is already provided by its parent class, it is known as Method Overriding.

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

C - Both of the above.

D - None of the above.