7) Write a C++ Program to demonstrate the functioning of a friend class.

 #include <iostream>

using namespace std;

class A {

private:

int a;

protected:

int b;

public:

A(int m,int n)

{

a=m;

b=n;

}

// friend class declaration

friend class B;

};

class B {

public:

void display(A& t)

{

cout << "Sqaure of varible a = "

<< t.a*t.a << endl;

cout << "Cube of variable  b = "

<< t.b*t.b;

}

};

int main()

{

cout<<"Friend class program "<<endl;

A ob1(2,3);

B ob2;

ob2.display(ob1);

return 0;

}

output:

Friend class program 

Sqaure of varible a = 4

Cube of variable  b = 9