10_frndexxample.cpp

#include<iostream>
using namespace std;
class c2;
class c1{
    int val;
    public:
    void intdata(int a){
        val = a;
    }
    void display(void){
        cout<<val<<endl;
    }
    friend void exchange(c1 &,c2 &);
    };
class c2{
    int value;
    public:
    void intdata(int b){
        value = b;
    }
    void display(void){
        cout<<value<<endl;
    }
    friend void exchange(c1 & ,c2&);
};
void exchange( c1 &x,c2 &y){
    int swap=x.val;
    x.val=y.value;
    y.value=swap;
}
int main(){
    c1 oc1;
    c2 oc2;

    oc1.intdata(22);
    oc2.intdata(44);
    exchange(oc1,oc2);
    cout<<"The value after exhange c1 : ";
    oc1.display();
    cout<<"The value after exhange c2 : ";
    oc2.display();
    return 0;
}