Which statement about a pure virtual function in C++ is correct?
class Base
{
public:
virtual void show() = 0;
};
Options
-
A.
A pure virtual function can never have any definition anywhere.
-
B.
A pure virtual function may have a definition, but the class containing it is still abstract.
-
C.
A pure virtual function must always be static.
-
D.
More than one of the above
-
E.
None of the above
Correct Answer (Detailed Explanation is Below)
B.
A pure virtual function may have a definition, but the class containing it is still abstract.
Detailed Explanation
Answer: (B) A pure virtual function may have a definition, but the class containing it is still abstract.
A pure virtual function is normally declared using = 0.
It is possible in C++ to provide a separate definition for a pure virtual function in certain situations. However, the class still remains abstract because the function is declared pure virtual.
The important point for an exam is that = 0 makes the function pure virtual; it does not simply mean that no definition can ever exist.
