Programs should also be tested to make sure that they don't do what they are not supposed to do. Tests should include correct and incorrect inputs, as well as nonsense inputs. Maintenance Bugs are found that need to be fixed Requirements change Components are reused Enhancements are made More than half of all software development effort is maintenance. Generally accomplished by some abbreviated version of the first four steps above. A comment is a non-compiled informational tidbit.
Comments make the text of the program easier to understand.
Document the program within the program . The included file should include declarations, but no executable code. Identifiers may only contain letters, numbers, and underscores. Reserved words cannot be used as identifiers. Executable statements are always terminated with a semicolon.