Explore topic-wise MCQs in Java.

This section includes 25 Mcqs, each offering curated multiple-choice questions to sharpen your Java knowledge and support exam preparation. Choose a topic below to get started.

1.

A Static method of an Interface should be accessed with _____ and a DOT operator.

A. Class Name
B. Interface Name
C. An object of a concrete class
D. None of the above
Answer» C. An object of a concrete class
Discussion
2.

A Superinterface is comparable to a Superclass. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
3.

Which is the missing code to successfully compile the below Java program with abstract classes and Interfaces?

A. @Override
B. @Override
C. @Override
D. All the above
Answer» B. @Override
Discussion
4.

Which is the missing java code in the class implementing an Interface below?

A. class Speaker implements Linein, Lineout
B. class Speaker implements Linein, Lineout
C. class Speaker implements Linein, Lineout
D. All the above
Answer» B. class Speaker implements Linein, Lineout
Discussion
5.

A Java static method can not be ___.

A. private or protected
B. final
C. abstract
D. All the above
Answer» E.
Discussion
6.

It is ___ to override the static method of an Interface in Java.

A. possible
B. not possible
C. -
D. -
Answer» C. -
Discussion
7.

The annotation used in Java to override the method of a super-class or interface by the subclass or implementing class is ___.

A. @override
B. @Override
C. @super
D. @subclass
Answer» C. @super
Discussion
8.

Is it possible to remove the keyword DEFAULT and make the method abstract again in an Interface, if the Interface belongs to a Closed-Source project?

A. Yes
B. No
C. -
D. -
Answer» B. No
Discussion
9.

The DEFAULT methods of an Interface are suitable mostly for ___ type of projects.

A. Open Source (Public Repositories)
B. Closed Source (Private Repositories)
C. -
D. -
Answer» B. Closed Source (Private Repositories)
Discussion
10.

Java Interface DEFAULT methods have ___ compatibility with the existing project code.

A. Forward
B. Backward
C. Backward and Forward
D. -
Answer» D. -
Discussion
11.

Java Interface static methods have ___ compatibility with the existing project code.

A. Forward
B. Backward
C. Both Forward and Backward
D. -
Answer» D. -
Discussion
12.

Java 8 (Java 1.8) introduced the ___ feature.

A. Default methods
B. Static methods
C. Default and Static methods
D. None of the above
Answer» D. None of the above
Discussion
13.

A Java Interface can not declare constructors. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
14.

A Java Class implementing an Interface can define a variable with the same name as that of the Interface constant. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
15.

A Class implementing an Interface can use ____ access modifier before the implemented methods.

A. private
B. protected
C. public
D. All the above
Answer» D. All the above
Discussion
16.

All Interface methods in Java are ____ by default.

A. public
B. abstract
C. public and abstract
D. None of the above
Answer» D. None of the above
Discussion
17.

All Interface variables are ___ by default in Java.

A. public
B. final
C. public and final
D. None
Answer» D. None
Discussion
18.

What is the output of the below Java program with an Interface?

A. No output
B. Implemented move() method.
C. Compiler error
D. None of the above
Answer» C. Compiler error
Discussion
19.

A Java Class inherits Constants and Methods of an Interface using ____ keyword.

A. INTERFACE
B. IMPLEMENTS
C. EXTENDS
D. All the above
Answer» C. EXTENDS
Discussion
20.

Choose a correct statement about Java Interfaces?

A. Interface contains only abstract methods by default.
B. A Java class can implement multiple interfaces
C. An Interface can extend or inherit another Interface.
D. All the above
Answer» E.
Discussion
21.

Choose the correct syntax below for defining an Interface in Java.

A. interface NAME
B. abstract interface NAME
C. public interface NAME
D. All the above
Answer» E.
Discussion
22.

A Java Interface is not considered a class. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
23.

An interface in Java is like a 100% ____.

A. abstract class
B. public class
C. inner class
D. anonymous class
Answer» B. public class
Discussion
24.

Which of the following is an incorrect statement about packages?

A. Interfaces specifies what class must do but not how it does
B. Interfaces are specified public if they are to be accessed by any code in the program
C. All variables in interface are implicitly final and static
D. All variables are static and methods are public if interface is defined pubic
Answer» E.
Discussion
25.

Which of the following is the correct way of implementing an interface salary by class manager?

A. class manager extends salary {}
B. class manager implements salary {}
C. class manager imports salary {}
D. none of the mentioned
Answer» C. class manager imports salary {}
Discussion