I'm considering https://www.goodreads.com/en/book/show/13136685-learn-c-the-hard-way by Zed Shaw.

I haven't read your appendix. I might have to! In short: 1. Consider just using hash maps and lists instead of "everything is an object" 2. When making classes, make them trivial to convert from/to JSON 3. When making classes, make them small and immutable. Consider using dataclasses.

You're referring to Appendix B?

I've either just used a map, or gone the "reflection" route with Gson or Jackson. I haven't really encountered the need to treat the objects as maps. If I were to do that, I guess I could just convert to Json and then convert to a map. My primary benefit in Java has simply been "less object stuff". Represent a domain entity with an immutable object, done. Don't write setters. Then try to build a "language" for working with those domain objects in a way that makes sense.

C has no objects, no class system, no built-in hash maps or lists, unless you implement them yourself from the constructs that C does provide.

It is certainly possible to write pure functions in C, but in idiomatic C, they are the exception, I would say.

Thank you @teodorlu