10.1) Subroutines

Subroutines are like functions in that part of the main program is separated off in a sub task and solved. The results are then returned to the main code and the program proceeds. Whereas functions are used to calculate a single value to return to the program, a subroutine is more general and is used to modify numerous variables. This is the most important difference.

Subroutines can help make programs clearer to read, break tasks down into manageable chunks, and it can be useful to create subroutines so that the code can be reused for other purposed without rewriting it.

Please see the next page for an example of a subroutine and a video explaining it.