C++ Primer Plus

Defining a Function

You can group functions into two categories: those that don’t have return values and those that do. Functions without return values are termed type void functions and have the following general form:

void functionName(parameterList){    statement(s)    return;          // optional}

Here parameterList specifies the types and number of arguments (parameters) passed to the function. This chapter more fully investigates this list later. The optional return statement marks the end of the function. Otherwise, the function terminates at the closing brace. Type void functions correspond to Pascal procedures, FORTRAN subroutines, and modern BASIC subprogram procedures. Typically, you use a void function to perform some sort of action. ...