Question

Is there any way I can access Private member variable of a class?

Editing:
Not from a member function or friend function but through an instance.

Answer 1

Just cast it around, shift memory and cast back. (didn’t compile the code, but you should get the idea).

class Bla
{
public:
    Bla() : x(15), str("bla") {}
private:
    int x;
    std::string str;
}

int main()
{
    Bla bla;

    int x = *((int*)(&bla));
    std::string str = *((std::string*)((int*)(&bla) + 1));

    std::cout << x << str;

    return 0;
}

Since this is an interview question, I won’t go into why you shouldn’t do that. 🙂

EDIT:
Classes with virtual functions will have virtual table pointer somewhere there as well. I’m not sure if & will give you address of vt or address of first data member.

Alignment is 4 by default (right?), so if member you are reading does not align, shift by 2 bytes to get to the next one.