Another good programming practice is to put subroutines which may be used in more than one program into a 'standard module'.

Standard modules are really libraries of subroutines which may be used in any program. The advantage of this are that..

• time is saved as the programmer does not have to write the same modules again.
• the subroutines have already been tested so they will work and there is no need to test them again.
• program will end up being shorter and therefore easier to modify.