ISRO | ISRO CS 2008 | Question 71

We can make a class abstract by
(A) Declaring it abstract using the virtual keyword
(B) Making at least one member function as virtual function
(C) Making at least one member function as pure virtual function
(D) Making all member function const

Answer: (C)
Explanation: An abstract class is a class that is designed to be specifically used as a base class. An abstract class contains at least one pure virtual function. A pure virtual function can be declared by using a pure specifier ( = 0 ) in the declaration of a virtual member function in the class declaration.

Option (C) is correct.
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