C Programming: Visual Quickstart Guide

Creating Functions That Return a Value

The final addition to making your functions as practical as the standard C library functions is to have them return values. This is accomplished using the return statement, which you've already been using in the main function. You can return any single value from your function:

return 1;

The returned value can even be based on a variable's value:

int num = 8;
return num;

Any function that returns a value must have a proper prototype and definition, both of which must indicate the type of value returned. You've already seen this with the main function (which returns an int). Here's another sample function definition:

int my_func (void) {
   return 27;
}

You can assign the returned values to variables when ...