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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 - Objects are stored on Stack.

A - True

B - False

Answer : B

Explaination

Objects are allocated memory in heap memory space.

Q 2 - Is an empty .java file a valid source file?

A - True

B - False

Answer : A

Explaination

True, an empty .java file is a valid source file.

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 - Which of the following is true about super class?

A - Variables, methods and constructors which are declared private can be accessed only by the members of the super class.

B - Variables, methods and constructors which are declared protected can be accessed by any subclass of the super class.

C - Variables, methods and constructors which are declared public in the superclass can be accessed by any class.

D - All of the above.

Answer : D

Explaination

All of the above are correct.

Q 5 - Inheritance represents

A - HAS-A relationship.

B - IS-A relationship.

Answer : B

Explaination

Inheritance represets IS-A relationship providing code reusablity . Consider the following statement: Circle is a Shape. Here Shape is super class and Circle is a child class extends the super class Shape.

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 composition?

A - Composition is a data structure.

B - Composition is a way to create an object.

C - Holding the reference of the other class within some other class is known as composition.

D - None of the above.

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.

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 - Which arithmetic operations can result in the throwing of an ArithmeticException?