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 - Primitive variables are stored on Stack.

A - True

B - False

Answer : A

Explaination

Primitive variables like int, float are stored on Stack.

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 int variable?

Answer : A

Explaination

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

Q 4 - What is polymorphism?

A - Polymorphism is a technique to define different objects of same type.

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

C - Polymorphism is a technique to define different methods of same type.

D - None of the above.

Answer : B

Explaination

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 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 - What is Set Interface?

A - Set is a collection of element which contains elements along with their key.

B - Set is a collection of element which contains hashcode of elements.

C - Set is a collection of element which cannot contain duplicate elements.

D - Set is a collection of element which can contain duplicate elements.

Answer : C

Explaination

Set 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 7 - When static binding occurs?

A - Static binding occurs during Compile time.

B - Static binding occurs during load time.

C - Static binding occurs during runtime.

D - None of the above.

Answer : A

Explaination

Static binding occurs during Compile time.

Q 8 - What is a transient variable?

A - A transient variable is a variable which is serialized during Serialization.

B - A transient variable is a variable that may not be serialized during Serialization.

C - A transient variable is a variable which is to be marked as serializable.

D - None of the above.

Answer : B

Explaination

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

A - Compilation Error.

B - RunTime Error: NoSuchMethodError.

C - Program will compile and run without any output.

D - Program will compile and run to show the required output.