So far this book has concentrating on getting a job done. Starting with the basics of programming, it has moved on to some aspects of efficiency and testing. This section has little to do with the way programs run, and is concerned with the more personal aspects of programming.
Some programs are one-offs, written quickly to solve a particular task and then discarded.
However, most programs will be in use for a few weeks at least, and possibly years. Writing with an eye to maintenance and amendment in the first stages makes future changes much easier - especially if the original author is not the one altering the program. Even if the original author does come back to the program, the reasons for or effects of particular code segments may not be immediately apparent. Far and away the most important factor in increasing the longevity of programs is the use of comments. These have already been covered in section 8.2.