prog3.cpp

/* Write a C++ Program with two classes ABC and XYZ with one integer data member
   in each class. Write member functions to read and display, place a friend
   function called max() in these classes which takes the data members.
   Demostrate using the main() function.

   Note: Here, one member is a member of one class and the other member is a
   member of some other class.

   Concept: Friend functions and reference variables.
*/

#include <iostream>

using namespace std;

class ABC;

class XYZ {
private:
  int x;

public:
  void setVal(int x) { this->x = x; }

  friend void max(ABC, XYZ);
};

class ABC {
private:
  int y;

public:
  void setVal(int y) { this->y = y; }

  friend void max(ABC, XYZ);
};

void max(ABC a, XYZ b) {
  if (a.y > b.x) {
    cout << "The largest number is " << a.y << endl;
  } else {
    cout << "The largest number is " << b.x << endl;
  }
}

int main() {
  ABC abc;
  XYZ xyz;

  int x, y;

  cout << "Enter the value for x: ";
  cin >> x;
  xyz.setVal(x);
  cout << "Enter the value for y: ";
  cin >> y;
  abc.setVal(y);

  max(abc, xyz);
  return 0;
}