Friend Function

• These are special functions which can access the private members of a class.
• Private and protected data of class can be accessed from a friend function.

Declaration of Friend Function

class className
{
    ......  ....   ........
    friend returntype functionname(argument/s);
    ......  ....   ........
}

Points to remember

• Friend of the class can be member of some other class.
• Friend can access the private or protected members of the class .
• These are non-members hence do not get this pointer.
• They can be used for message passing between the classes since friends can be friend of more than one class,.

• This class can be declared anywhere i.e in public, protected or private section in the class.

  E.g of Friend Function

  class  base
  {
      int val1,val2;
     public:
      void get()
          {
             cout<<"Enter two values:";
             cin>>val1>>val2;
          }
          friend float mean(base ob);
      };
      float mean(base ob)
      {
         return float(ob.val1+ob.val2)/2;
      }
      void main()
      {
          clrscr();
          base obj;
          obj.get();
          cout<<"\n Mean value is : "<<mean(obj); 
          getch();
  }