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 correct syntax for main method of a java class?

A - public static int main(String[] args)

B - public int main(String[] args)

C - public static void main(String[] args)

D - None of the above.

Answer : C

Explaination

Correct syntax is public static void main(String[] args).

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 char variable?

Answer : A

Explaination

char variable has default value of '\u0000' if defined as an instance/static variable.

Q 4 - Which of the following is true about protected access modifier?

A - Variables, methods and constructors which are declared protected can be accessed by any class.

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

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

D - None of the above.

Answer : B

Explaination

Variables, methods, and constructors which are declared protected can be accessed by any class lying in the same package.

Q 5 - What is class variable?

A - class variables are static variables within a class but outside any method.

B - class variables are variables defined inside methods, constructors or blocks.

C - class variables are variables within a class but outside any method.

D - None of the above.

Answer : A

Explaination

Class variables are variables declared with in a class, outside any method, with the static keyword.

Q 6 - Can be constructor be made final?

A - True.

B - False.

Answer : B

Explaination

No, this is not possible.

Q 7 - Method Overriding is an example of

A - Static Binding.

B - Dynamic Binding.

C - Both of the above.

D - None of the above.

Answer : B

Explaination

Method Overriding is example of dynamic Binding.

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?

Answer : A

Explaination

Integer / and % can result in the throwing of an ArithmeticException.

Q 10 - What is currentThread()?

A - It is a Thread public static method used to obtain a reference to the current thread.

B - It is a thread's instance method used to get thread count.

C - It is a object's public static method used obtain a reference to the current thread.

D - It is a object's instance method used to get thread count.

Answer : A

Explaination

currentThread() is a public static method of Thread class used to obtain a reference to the current thread.

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