Explore topic-wise MCQs in Object Oriented Programming.

This section includes 36 Mcqs, each offering curated multiple-choice questions to sharpen your Object Oriented Programming knowledge and support exam preparation. Choose a topic below to get started.

1.

Is it necessary that all the abstract methods must be defined from an abstract class?

A. Yes, depending on code
B. Yes, always
C. No, never
D. No, if function is not used, no definition is required
Answer» C. No, never
Discussion
2.

How many abstract classes can a single program contain?

A. At most 1
B. At least 1
C. At most 127
D. As many as required
Answer» E.
Discussion
3.

It is _________________________ to have an abstract method.

A. Not mandatory for an static class
B. Not mandatory for a derived class
C. Not mandatory for an abstract class
D. Not mandatory for parent class
Answer» D. Not mandatory for parent class
Discussion
4.

Can abstract classes have static methods (Java)?

A. Yes, always
B. Yes, but depends on code
C. No, never
D. No, static members can’t have different values
Answer» B. Yes, but depends on code
Discussion
5.

Abstract class can’t be final in java.

A. True
B. False
Answer» B. False
Discussion
6.

The abstract classes in java can _________________

A. Implement constructors
B. Can’t implement constructor
C. Can implement only unimplemented methods
D. Can’t implement any type of constructor
Answer» B. Can’t implement constructor
Discussion
7.

Use of pointers or reference to an abstract class gives rise to which among the following feature?

A. Static Polymorphism
B. Runtime polymorphism
C. Compile time Polymorphism
D. Polymorphism within methods
Answer» C. Compile time Polymorphism
Discussion
8.

Which among the following is an important use of abstract classes?

A. Header files
B. Class Libraries
C. Class definitions
D. Class inheritance
Answer» C. Class definitions
Discussion
9.

We ___________________ to an abstract class.

A. Can create pointers
B. Can create references
C. Can create pointers or references
D. Can’t create any reference, pointer or instance
Answer» D. Can’t create any reference, pointer or instance
Discussion
10.

Abstract classes can ____________________ instances.

A. Never have
B. Always have
C. Have array of
D. Have pointer of
Answer» B. Always have
Discussion
11.

Abstract class A has 4 virtual functions. Abstract class B defines only 2 of those member functions as it extends class A. Class C extends class B and implements the other two member functions of class A. Choose the correct option below.

A. Program won’t run as all the methods are not defined by B
B. Program won’t run as C is not inheriting A directly
C. Program won’t run as multiple inheritance is used
D. Program runs correctly
Answer» E.
Discussion
12.

If a class is extending/inheriting another abstract class having abstract method, then _______________________

A. Either implementation of method or making class abstract is mandatory
B. Implementation of the method in derived class is mandatory
C. Making the derived class also abstract is mandatory
D. It’s not mandatory to implement the abstract method of parent class
Answer» B. Implementation of the method in derived class is mandatory
Discussion
13.

If there is an abstract method in a class then, ________________

A. Class must be abstract class
B. Class may or may not be abstract class
C. Class is generic
D. Class must be public
Answer» B. Class may or may not be abstract class
Discussion
14.

Can abstract class have main() function defined inside it?

A. Yes, depending on return type of main()
B. Yes, always
C. No, main must not be defined inside abstract class
D. No, because main() is not abstract function
Answer» C. No, main must not be defined inside abstract class
Discussion
15.

Which among the following best describes abstract classes?

A. If a class has more than one virtual function, it’s abstract class
B. If a class have only one pure virtual function, it’s abstract class
C. If a class has at least one pure virtual function, it’s abstract class
D. If a class has all the pure virtual functions only, then it’s abstract class
Answer» D. If a class has all the pure virtual functions only, then it’s abstract class
Discussion
16.

An abstract class can define ____ inside of it.

A. Inner abstract class
B. Inner concrete class
C. static methods
D. All the above
Answer» E.
Discussion
17.

Abstract classes support ____ inheritance.

A. Multiple
B. Multilevel
C. -
D. -
Answer» C. -
Discussion
18.

Just like an Interface, you can define constants in abstract classes in Java. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
19.

Choose correct statements about an Abstract class in Java?

A. An abstract class implementing an Interface, need not implement methods of an interface
B. An abstract class extending another abstract class, need not define methods of the super abstract class.
C. The first subclass of an abstract class should define all the abstract methods inherited from all the interfaces and super abstract classes.
D. All the above
Answer» E.
Discussion
20.

Choose a correct statement about abstract classes?

A. An abstract class can extend a concrete class
B. An abstract class can extend another abstract class
C. An abstract class can implement any number of interfaces.
D. All the above.
Answer» E.
Discussion
21.

What is the output of the below Java code with an abstract class and inner class?

A. Compiler error
B. Inner class is present..
C. No output
D. None of the above
Answer» C. No output
Discussion
22.

An abstract class with 100% abstract methods is equivalent to ______.

A. Concrete class
B. Virtual Class
C. Interface
D. All the above
Answer» D. All the above
Discussion
23.

An object of multi-level inherited abstract class can not be created in memory? State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
24.

What is the output of the below Java program with multiple abstract classes?

A. Editor method
B. Author method
C. Editor method
D. Compiler error
Answer» D. Compiler error
Discussion
25.

What is the output of the below Java program with an abstract class?

A. Compiler error
B. Inside Constructor of Coffee..
C. Inside Constructor of ColdCoffee..
D. Inside Constructor of Coffee..
Answer» C. Inside Constructor of ColdCoffee..
Discussion
26.

Does the below Java code with abstract method compile?

A. NO
B. YES
C. -
D. -
Answer» B. YES
Discussion
27.

An abstract class in Java usually contains one or more abstract ____.

A. constructors
B. methods
C. variables
D. None
Answer» C. variables
Discussion
28.

Choose a correct implementation of an Abstract class in the below Java code?

A. abstract class ClassA { }
B. abstract class ClassB
C. abstract class ClassC
D. All the above
Answer» E.
Discussion
29.

Which is the opposite of an Abstract Class?

A. Interface
B. concrete class
C. -
D. -
Answer» C. -
Discussion
30.

Can you create an object from an abstract class in Java?

A. Yes
B. No
C. -
D. -
Answer» C. -
Discussion
31.

To create an Abstract class, the keyword "class" is also required. State TRUE or FALSE.

A. TRUE
B. FALSE
C. -
D. -
Answer» B. FALSE
Discussion
32.

An abstract class in Java can be created using the keyword ____.

A. final
B. interface
C. abstract
D. static
Answer» D. static
Discussion
33.

USE_OF_POINTERS_OR_REFERENCE_TO_AN_ABSTRACT_CLASS_GIVES_RISE_TO_WHICH_AMONG_THE_FOLLOWING_FEATURE??$

A. Static Polymorphism
B. Runtime polymorphism
C. Compile time Polymorphism
D. Polymorphism within methods
Answer» C. Compile time Polymorphism
Discussion
34.

Abstract class can’t be final in java.$#

A. True
B. False
Answer» B. False
Discussion
35.

The_abstract_classes_in_java_can__________________$

A. Implement constructors
B. Can’t implement constructor
C. Can implement only unimplemented methods
D. Can’t implement any type of constructor
Answer» B. Can‚Äö√Ñ√∂‚àö√ë‚àö¬•t implement constructor
Discussion
36.

Can_abstract_classes_have_static_methods_(Java)?

A. Yes, always
B. Yes, but depends on code
C. No, never
D. No, static members can’t have different values
Answer» B. Yes, but depends on code
Discussion