171: Sidetrip

The function prototype for the volume function is particularly simple, because there are no ordinary arguments. In general, function prototypes must include a data-type declaration for each ordinary argument.

return data type function name (data type of parameter 1, 
                                  ..., 
                                  data type of parameter n); 

The following, for example, is a function prototype for a scaled_volume function:

double scaled_volume (double);