Robert Martin

One word: care. That’s really the topic of this book.

The @author field of a Javadoc tells us who we are. We are authors. And one thing about authors is that they have readers. Indeed, authors are responsible for communicating well with their readers.

the ratio of time spent reading vs. writing is well over 10:1. We are constantly reading old code as part of the effort to write new code.

Because this ratio is so high, we want the reading of code to be easy, even if it makes the writing harder. Of course there’s no way to write code without reading it, so making it easy to read actually makes it easier to write.

Choosing good names takes time but saves more than it takes.

If a name requires a comment, then the name does not reveal its intent.

Back in my days working in the Bell Labs Software Production Research organization (Production, indeed!) we had some back-of-the-envelope findings that suggested that consistent indentation style was one of the most statistically significant indicators of low bug density. We want it to be that architecture or programming language or some other high notion should be the cause of quality; as people whose supposed professionalism owes to the mastery of tools and lofty design methods, we feel insulted by the value that those factory-floor machines, the coders, add through the simple consistent application of an indentation style.

In our profession, we desperately need all the help we can get. If a clean shop floor reduces accidents, and well-organized shop tools increase productivity, then I’m all for them.

Clean code always looks like it was written by someone who cares. There is nothing obvious that you can do to make it better. All of those things were thought about by the code’s author, and if you try to imagine improvements, you’re led back to where you are, sitting in appreciation of the code someone left for you—code left by someone who cares deeply about the craft.

None of these different schools is absolutely right. Yet within a particular school we act as though the teachings and techniques are right. After all, there is a right way to practice Hakkoryu Jiu Jitsu, or Jeet Kune Do. But this rightness within a school does not invalidate the teachings of a different school.

As we’ll see later on, even if the container is a List, it’s probably better not to encode the container type into the name.