Which of the following is the correct syntax for declaring a pure virtual function in C++?
class Base
{
public:
virtual void display() = 0;
};
Options
-
A.
virtual void display();
-
B.
virtual void display() = 0;
-
C.
void virtual display() = 1;
-
D.
More than one of the above
-
E.
None of the above
Correct Answer (Detailed Explanation is Below)
B.
virtual void display() = 0;
Detailed Explanation
Answer: (B) virtual void display() = 0;
A pure virtual function is declared by using the virtual keyword and assigning = 0 to the function declaration.
For example:
virtual void display() = 0;
The = 0 does not mean that the function returns zero. It specifies that the function is pure virtual.
A class containing at least one such function becomes an abstract class.
