/*I just started coding few days and was going through friend function in cpp and it was saying friend used out of class I can’t understand , even I used it inside the class .
*/

> `#include<iostream>
using namespace std;
class Y;
class X{
int data;
public:    
void setvalue(int value){
data=value;
>             }
friend void add(X , Y );        
> };
class Y{
int num;
public:    
void setvalue(int value){
num=value;
friend void add(X , Y); 
>             }
> };
void add(X o1, Y o2)//x ka o1 hai aur y ka o2 hai{
cout<<"gives-"<<o1.data+o2.num;
> };

int main(){
X a;
a.setvalue(5);
Y b;
b.setvalue(6);
add(a,b);
return 0;
> }`