Seven Rules for Beginning Programmers

A little while ago Phil Wadler posted “VS Naipaul’s Rules for Beginners,” listing the famous author’s seven rules for beginning writers. Upon reading them it occurred to me that, with a little adaptation, they could equally apply to beginning programmers. So, with apologies to Mr. Naipaul, here are my “Rules for Beginners:”

1. Do not write long procedures. A procedure should not have more than ten or twelve lines.
2. Each procedure should have a clear purpose. It should not overlap in purpose with the procedures that went before or come after. A good program is a series of clear, non-overlapping procedures.
3. Do not use fancy language features. If you’re using something more than variable declarations, procedure calls, control flow statements and arithmetic operators, there is something wrong. The use of simple language features compels you to think about what you are writing. Even difficult algorithms can be broken down into simple language features.
4. Never use language features whose meaning you are not sure of. If you break this rule you should look for other work.
5. The beginner should avoid using copy and paste, except when copying code from one program they have written to a new one they are writing. Use as few files as possible.
6. Avoid the abstract. Always go for the concrete. [Ed. note: This one applies unchanged.]
7. Every day, for six months at least, practice programming in this way. Short statements; short, clear, concrete procedures. It may be awkward, but it’s training you in the use of a programming language. It may even be getting rid of the bad programming language habits you picked up at the university. You may go beyond these rules after you have thoroughly understood and mastered them.