What is friend function ?

A friend function is a function that access private data variables of another class. The measure different between an ordinary class function and a member function is that the ordinary function access the object that involves the member to be passed by reference or value.

Example :-                      class sum

                                                     {

                                                         Private:

                                                          Int a,b,c;

                                                          Public:

                                                           Void get dada ()

                                                                    {

                                                                         Cout>>a>>b;

                                                                     }

                                                              Void show data ()

                                                                     {

                                                                          Cout <<”sum”<<c

                                                                         Friend  void(sum x)

                                                                      }

                                                            Void  add (sum x)

                                                                            {

                                                                                      x.c=x.a+x.b

                                                                             }

                                                                   Void main()

                                                                        {

                                                                              Sum obj;

                                                             obj.get.data();

                                                                add(obj)

                                                            obj.showdata();

                                                                        }

                                             };