166: Mainline

Member functions can have ordinary arguments in addition to the special class-object argument. You might, for example, have a member function named scaled_volume that multiplies the volume of its class-object argument by a scale factor supplied as an ordinary argument:

*-- Class-object argument 
| 
|                  *-- Ordinary argument 
|                  | 
v                  v 
x.scaled_volume (0.95) 

The definition of a scaled_volume member function is similar to that of a volume member function. The only difference is the addition of an ordinary parameter, scale_factor:

class box_car { 
  public: double height, width, length; 
          double scaled_volume (double scale_factor) { 
            return scale_factor * height * width * length; 
          } 
};