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 a class in java?

A - A class is a blue print from which individual objects are created. A class can contain fields and methods to describe the behavior of an object.

B - class is a special data type.

C - class is used to allocate memory to a data type.

D - none of the above.

Answer : A

Explaination

A class is a blue print from which individual objects are created. A class can contain fields and methods to describe the behavior of an object.

Q 2 - What is the size of double variable?

Answer : D

Explaination

The double data type is represented by double-precision 64-bit IEEE 754 floating point.

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 private access modifier?

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

B - Variables, methods and constructors which are declared private can be accessed by any class lying in same package.

C - Variables, methods and constructors which are declared private in the superclass can be accessed only by its child class.

D - None of the above.

Answer : A

Explaination

Private access modifier is used to restrict access to variables, methods and constructors to member of same class only.

Q 5 - What is an immutable object?

A - An immutable object can be changed once it is created.

B - An immutable object can't be changed once it is created.

C - An immutable object is an instance of an abstract class.

D - None of the above.

Answer : B

Explaination

An immutable object can't be changed once it is created. String objects are immutable.

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 - 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 - What is synchronization?

A - Synchronization is the capability to control the access of multiple threads to shared resources.

B - Synchronization is the process of writing the state of an object to another object.

C - Synchronization is the process of writing the state of an object to byte stream.

D - None of the above.

Answer : A

Explaination

Synchronization is the capability to control the access of multiple threads to shared resources. synchronized keyword in java provides locking which ensures mutual exclusive access of shared resource and prevent data race.

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.

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