The WordPress Codex is a great resource for new developers, but as many have noted, it is far from complete and isn’t necessarily always accurate. While there are myriad web-based alternatives that can serve as a guide to WordPress’ inner workings, there is no better aid than Core itself.
Intimidated by all of those files? Don’t be. They’re actually rather well organized, and with a bit of guidance, one can easily locate the appropriate function for a given task.
As you’ll find, there are even many useful functions that don’t even appear in Core. I’ll provide an overview of how Core is organized, discuss why certain functions exist only in wp-admin, and highlight some of the exceptions to the organizational rule that lead to frustration when first exploring Core.
With this understanding, not only can one more efficiently identify the proper function for a given situation, but also give back to the community by updating the Codex; it’s just a Wiki after all.
