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

class Speaker implements Linein, Lineout

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

Closed Source (Private Repositories)

Open Source (Public Repositories)

Closed Source (Private Repositories)

Choose a correct statement about Java Interfaces?

Interface contains only abstract methods by default.

A Java class can implement multiple interfaces

An Interface can extend or inherit another Interface.

Which of the following is an incorrect statement about packages?

Interfaces specifies what class must do but not how it does

Interfaces are specified public if they are to be accessed by any code in the program

All variables in interface are implicitly final and static

All variables are static and methods are public if interface is defined pubic

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

class manager imports salary {}

class manager extends salary {}

class manager implements salary {}

class manager imports salary {}

25 + Mcqs in Interfaces in Java Page 1 McqOptions

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

Explore topic-wise MCQs in Java.

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

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

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

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

A Java static method can not be ___.

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

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

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?

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

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

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

Java 8 (Java 1.8) introduced the ___ feature.

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

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

All Interface methods in Java are ____ by default.

All Interface variables are ___ by default in Java.

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

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

Choose a correct statement about Java Interfaces?

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

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

An interface in Java is like a 100% ____.

Which of the following is an incorrect statement about packages?

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