Friend function

Question

what can i do using friend function...if you have any idea or coding problem relating to this,plz help me.

Answer 1

This is the best use i have to come across..
class ComplexNo
{
private:
    int real, imag;
public:
    Complex(int r = 0, int i =0)
    {  real = r;   imag = i; }
    friend ostream & operator << (ostream &out, const Complex &c);
    friend istream & operator >> (istream &in,  Complex &c);
};

ostream & operator << (ostream &out, const Complex &c)
{
    out << c.real;
    out << "+i" << c.imag << endl;
    return out;
}
istream & operator >> (istream &in,  Complex &c)
{
    cout << "Enter Real Part ";
    in >> c.real;
    cout << "Enter Imagenory Part ";
    in >> c.imag;
    return in;
}

Now
ComplexNo c1,c2;
cin>>c1>>c2;
cout<<c1<<c2;
type operation are possible. so they can be treated as normal variables for input output purposes.