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 of the following is the default value of an instance variable?

A - null

B - 0

C - Depends upon the type of variable

D - Not assigned

Answer : C

Explaination

Instance variables are assigned default values based on their types. For example, int variable is assigned 0 and an object type variable is assigned null as default value.

Q 2 - Is an empty .java file a valid source file?

A - True

B - False

Answer : A

Explaination

True, an empty .java file is a valid source file.

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

Answer : A

Explaination

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

Q 4 - Which of the following is false about String?

A - String is immutable.

B - String can be created using new operator.

C - String is a primary data type.

D - None of the above.

Answer : C

Explaination

String is a object.

Q 5 - What is an immutable object?

A - An immutable object can be changed once it is created.

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

C - An immutable object is an instance of an abstract class.

D - None of the above.

Answer : B

Explaination

An immutable object can't be changed once it is created. String objects are immutable.

Q 6 - What is JRE?

A - JRE is a java based GUI application.

B - JRE is an application development framework.

C - JRE is an implementation of the Java Virtual Machine which executes Java programs.

D - None of the above.

Answer : C

Explaination

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 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.