Write a program for friend function in c++

 Que-Make a program for friend function?

#include<iostream>
using namespace std;

class first
{
    int a;
    public:
    void getdata ()
    {
    a=10;
    }
    friend  class krishna ;

};
class krishna
{
   public:
   void display (first &t)
     {  
    cout<<"no. is "<<t.a;  
    }
};
int main()
{
   first  c;
   krishna  b;
   c.getdata();
   b.display(c);
    return 0;
} 

result:-