Beginning C: From Novice to Professional, Fourth Edition

CHAPTER 8Structuring Your Programs

I mentioned in Chapter 1 that breaking up a program into reasonably self-contained units is basic to the development of any program of a practical nature. When confronted with a big task, the most sensible thing to do is break it up into manageable chunks. You can then deal with each small chunk fairly easily and be reasonably sure that you've done it properly. If you design the chunks of code carefully, you may be able to reuse some of them in other programs.

One of the key ideas in the C language is that every program should be segmented into functions that are relatively short. Even with the examples you've seen so far that were written as a single function, main(), other functions are also involved because ...