Thread: operators << and >>

1. You declare it to be a friend only in the class body.

Code:

class kom
{
friend ostream& operator<<(ostream& out, const kom&);
//other data
}; //<===Don't forget the semicolon after the class declaration

you define it elsewhere without the friend directive because outside the class it would mean it's a friend to the global scope, which wouldn't be much use

Code:

class kom
{
//other data
};

//defined outside the scope of kom
ostream& operator<<(ostream& out, const kom&)
{
//don't use cout, cout is the standard output, you want 
//to use any output stream such as a file or string stream or any
//other stream object
  out <<a<<b<<d<<x<<y<<'\n';
  return out; //remember to return it.
}

now you can use it as such

Code:

int main()
{
  ofStream outfile("output.txt");
  ostringstream outsstream;
  kom aKom;
  //do whatever it is you want with your class
  cout << aKom;
  outfile << aKom;
  outsstream << aKom;
  return 0;
}