It's very easy not to write a book.
Mostly since it's such an awful lot of work. You'll first need to figure out what you're going to write about, and find an angle that makes it interesting enough for potential readers to buy the book and spend the time to finish it. The writing itself is hard work as well, and may take several years. Along the way you'll be telling yourself things that will keep you from finishing the task: I'm not doing anything original here. Nobody will be interested. Somebody else wrote a better book about this than I could ever do. If I don't cover topic B as well, it's not going to be a useful book at all.
During a recent run of my Advanced Web Application Architecture training, we discussed the distinction between infrastructure code and non-infrastructure code, which I usually call core code.
One of the participants summarized the difference between the two as: "everything in your vendor directory is infrastructure code".
I don't agree with that, and I will explain why in this article.
Here are some rules I use for working with dynamic arrays. It's pretty much a Style Guide for Array Design, but it didn't feel right to add it to the Object Design Style Guide, because not every object-oriented language has dynamic arrays. The examples in this post are written in PHP, because PHP is pretty much Java (which might be familiar), but with dynamic arrays instead of built-in collection classes and interfaces.