Java Online Quiz


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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 boolean variable?

A - 8 bit

B - 16 bit

C - 32 bit

D - not precisely defined

Answer : B

Explaination

The boolean data type can take either true or false, but its "size" isn't precisely defined.

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

A - 0

B - 0.0

C - null

D - not defined

Answer : A

Explaination

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

Answer : A

Explaination

It is the process where one object acquires the properties of another. With the use of inheritance the information is made manageable in a hierarchical order.

Q 6 - Composition represents

A - HAS-A relationship.

B - IS-A relationship.

Answer : A

Explaination

Holding the reference of the other class within some other class is known as composition. It represents a HAS-A relationship. For example, a Student has a Pen. Here Student class has Pen as its instance variable.

Answer : C

Explaination

Holding the reference of the other class within some other class is known as composition. It represents a HAS-A relationship. For example, a Student has a Pen. Here Student class has Pen as its instance variable.

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.

Answer : A

Explaination

Runtime polymorphism or dynamic method dispatch is a process in which a call to an overridden method is resolved at runtime rather than at compile-time. In this process, an overridden method is called through the reference variable of a superclass.

Answer : B

Explaination

A program is expected to recover if an exception occurs.

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