Becoming a Better Programmer

Chapter 16. Keep It Simple

Simplicity is the ultimate sophistication.

Leonardo da Vinci

You’ve heard the advice before: “KISS.” Keep it simple, stupid. Exactly how stupid do you have to be to get that wrong? Simplicity is an undoubtedly excellent objective; you should certainly strive for it in your code. No programmer yearns to work with overly complex code. Simple code is transparent; its structure is clear, it does not hide bugs, it is easy to learn, and easy to work with.

So why isn’t all code like that?

In the developer world, there are two kinds of simplicity: the wrong sort and the right sort. The “simplicity” we are looking for specifically does not mean: write your code the easiest way you can, cut corners, ignore all the nasty complicated stuff (brush it all under the rug and hope it goes away), and generally be a programming simpleton.

Oh, if only it were that easy. Too many programmers in the real world do write “simple” code like this. Their brain does not engage. Some of them don’t even realise that they’re doing anything wrong; they just don’t think enough about the code they’re writing, and fail to appreciate all of the inherent subtle complexities.

Such a mindless approach leads not to simple code, but to simplistic code. Simplistic code is incorrect code. Because it is ill-thought through, it doesn’t perform exactly as required—often it only covers the obvious “main case,” ignoring error conditions, or it does not correctly handle the less likely inputs. For ...