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 byte variable?

Answer : A

Explaination

Byte 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 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 - Dynamic binding uses which information for binding?

A - type.

B - object.

C - Both of the above.

D - None of the above.

Answer : B

Explaination

Dynamic binding uses object information for binding.

Q 8 - What invokes a thread's run() method?

A - JVM invokes the thread's run() method when the thread is initially executed.

B - Main application running the thread.

C - start() method of the thread class.

D - None of the above.

Answer : A

Explaination

After a thread is started, via its start() method of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

Q 9 - Can try statements be nested?

A - True.

B - False.

Answer : A

Explaination

Yes, try statements be nested.

Q 10 - Which of the following is a marker interface?

A - serializable

B - comparable

C - cloneable

D - none of the above.

Answer : A

Explaination

serializable is a marker interface.

java_questions_answers.htm