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.

Questions and Answers

Q 1 - What of the following is the default value of a local variable?

A - null

B - 0

C - Depends upon the type of variable

D - Not assigned

Answer : D

Explaination

Local variables are not assigned any value by default.

Q 2 - What is the size of char variable?

A - 8 bit

B - 16 bit

C - 32 bit

D - 64 bit

Answer : B

Explaination

The char data type is represented by single 16-bit Unicode character.

Minimum value: '\u0000' (or 0)

Maximum value: '\uffff' (or 65,535)

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

A - 0

B - 0.0

C - null

D - not defined

Answer : A

Explaination

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

Answer : B

Explaination

String object is immutable so that once it is created a String object cannot be changed. Since String is immutable it can safely be shared between many threads which are considered very important for multithreaded programming.

Answer : A

Explaination

Variables defined inside methods, constructors or blocks are called local variables. The variable will be declared and initialized within the method and it will be destroyed when the method has completed.

Q 6 - Can be constructor be made final?

A - True.

B - False.

Answer : B

Explaination

No, this is not possible.

Answer : A

Explaination

If a class has multiple functions by same name but different parameters, it is known as Method Overloading.

Answer : A

Explaination

Deserialization is the process of restoring state of an object from a byte stream.

Answer : A

Explaination

The garbage collector invokes an object's finalize() method when it detects that the object has become unreachable.

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
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