Which of the following best describes abstraction in OOP?

248.

Ability for an object to change its behaviour according to how it is being used

Process of deriving the new class from already existing class

When we need to only inherit from a certain class, but not need to instantiate objects of that class

Act of concealing the functionality of a class so that the internal operations are hidden, and irrelevant, to the programmer

All of above

View Description

The word abstract means a concept or an idea not associated with any specific instance.

In programming we apply the same meaning of abstraction by making classes not associated with any specific instance.

The abstraction is done when we need to only inherit from a certain class, but not need to instantiate objects of that class. In such case the base
class can be regarded as "Incomplete". Such classes are known as an "Abstract Base Class".

Abstract Base Class

There are some important points about Abstract Base Class :

An Abstract Base class can not be instantiated; it means the object of that class can not be created.

Class having abstract keyword and having, abstract keyword with some of its methods (not all) is known as an Abstract Base Class.

Class having Abstract keyword and having abstract keyword with all of its methods is known as pure Abstract Base Class.

The method of abstract class that has no implementation is known as