C++ Friend Interview Question:

What is the output of this program?

#include <iostream>
using namespace std;
class sample
{
int width, height;
public:
void set_values (int, int);
int area () {return (width * height);}
friend sample duplicate (sample);
};
void sample::set_values (int a, int b)
{
width = a;
height = b;
}
sample duplicate (sample rectparam)
{
sample rectres;
rectres.width = rectparam.width * 2;
rectres.height = rectparam.height * 2;
return (rectres);
}
int main ()
{
sample rect, rectb;
rect.set_values (2, 3);
rectb = duplicate (rect);
cout << rectb.area();
return 0;
}

a) 20
b) 16
c) 24

Submitted by: Murtaza

c) 24
Explanation:
In this program, we are using the friend function for duplicate function and calculating the area of the rectangle.
Output:
$ g++ friend1.cpp
$ a.out
24
Submitted by: Murtaza