I was recently asked this in an interview. Given the code:
class A{
public:
void f() { cout << "f in A" << endl; }
};
class B : public A{
public:
void g() { cout << "g in B" << endl; }
};
int main()
{
B *p2 = new B;
}
Which function does pointer p2 point to ?
Thanks
p2 is not a function pointer. p2 is just pointing to the memory allocated by new B, not a function.
Hmpf. p2 points to an instance of class B. So it could also point
-implementation specific and by accident- point to function g (if you apply some strange casts),
but this is rather pointless. p2 just points to an instance of class B, and if you like, you can invoke that instances method g. And if you are even more adventurous, you can even invoke method f of B's base class A's method f. Anything else is just implementation dependant and makes no sense.
p2 does not point to a function but to an instance of class B. Not only is it not a function pointer (as the other answers have pointed out), but the address it points to is not also the address of any function in almost any implementation. If class B had non-static data members, p2 would also coincide with the address of the first non-static data member (but it would not point to that as its not a pointer to that type of object!). However, this does not work for member methods: member function pointers don't depend on the object.
Very strange to have such a nonsense question in an interview. Perhaps the interviewers wanted to show their ignorance of basic programming.
