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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 - Static functions can be accessed using null reference.

A - True

B - False

Answer : A

Explaination

True, Static functions can be accessed via class name or via null reference.

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 long variable?

Answer : C

Explaination

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

Q 4 - What is polymorphism?

A - Polymorphism is a technique to define different objects of same type.

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

C - Polymorphism is a technique to define different methods of same type.

D - None of the above.

Answer : B

Explaination

Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object.

Q 5 - What is local variable?

A - Variables defined inside methods, constructors or blocks are called local variables.

B - Variables defined outside methods, constructors or blocks are called local variables.

C - Static variables defined outside methods, constructors or blocks are called local variables.

D - None of the above.

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 - What is JRE?

A - JRE is a java based GUI application.

B - JRE is an application development framework.

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

D - None of the above.

Answer : C

Explaination

Java Runtime Environment is an implementation of the Java Virtual Machine which executes Java programs. It provides the minimum requirements for executing a Java application.

Q 7 - What is function overloading?

A - Methods with same name but different parameters.

B - Methods with same name but different return types.

C - Methods with same name, same parameter types but different parameter names.

D - None of the above.

Answer : A

Explaination

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

Q 8 - Does garbage collection guarantee that a program will not run out of memory?

A - True.

B - False.

Answer : B

Explaination

Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection.

Q 9 - Can try statements be nested?

A - True.

B - False.