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 correct syntax for main method of a java class?

A - public static int main(String[] args)

B - public int main(String[] args)

C - public static void main(String[] args)

D - None of the above.

Answer : C

Explaination

Correct syntax is public static void main(String[] args).

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 short variable?

Answer : B

Explaination

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

Q 4 - What is the default value of Object variable?

Answer : C

Explaination

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

Q 5 - What is Abstraction?

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

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

C - It refers to the ability to make a class abstract in OOP.

D - None of the above.

Answer : C

Explaination

It refers to the ability to make a class abstract in OOP. It helps to reduce the complexity and also improves the maintainability of the system.

Q 6 - What is JIT compiler?

A - JIT improves the runtime performance of computer programs based on bytecode.

B - JIT is an application development framework.

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

D - None of the above.

Answer : A

Explaination

JIT, Just In-Time Compiler, improves the runtime performance of computer programs based on bytecode.

Q 7 - What is true about a final class?

A - class declard final is a final class.

B - Final classes are created so the methods implemented by that class cannot be overridden.

C - It can't be inherited.

D - All of the above.

Answer : D

Explaination

Final classes are created so the methods implemented by that class cannot be overridden. It can't be inherited. These classes are declared final.

Q 8 - What is synchronization?

A - Synchronization is the capability to control the access of multiple threads to shared resources.

B - Synchronization is the process of writing the state of an object to another object.

C - Synchronization is the process of writing the state of an object to byte stream.

D - None of the above.

Answer : A

Explaination

Synchronization is the capability to control the access of multiple threads to shared resources. synchronized keyword in java provides locking which ensures mutual exclusive access of shared resource and prevent data race.

Q 9 - Can a top level class be private or protected?

A - True.

B - False.

Answer : B

Explaination

No, a top level class can not be private or protected. It can have either "public" or no modifier.

Q 10 - This is the parent of Error and Exception classes.

Answer : A

Explaination

Throwable is the parent of both Error and Exception class.

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