How to learn frameworks?

Question

Objective-C

How to learn a language I understand it comes from reading several books about the language.
I understand that the next step is to learn basic frameworks like Foundation and UIKit.
But I can't quite figure out how to do it.
Suppose, in order to create a cell in a UITableView, it is necessary to fill in some data on the ViewController, for example UITextField, and then from the class responsible for the implementation of the ViewController with UITextField send a notification to the class with UITableView about data transfer. I learned about it from the video tutorial.
How was I supposed to know this? The documentation simply writes a class of the UITableView type and all its methods, but nowhere does it say that in order to do this, you need to send a notification and implement the table overload method.
I want to know how can I study the documentation ? On what basis is this done?
What should be done to understand how a certain object works?
Learn all its methods and its description ?

Answer 1

0. Framework (that's how it's more correct)
1. don't watch video tutorials (infa becomes obsolete very quickly)
2. Pull up English (because it's relevant in the original source)
3. Practice, practice and practice.

Answer 2

The documentation is not only an API Reference with a description of the class methods, but also a lot of manuals from Apple. Here, for example, is a guide to UITableView, where quite a lot of the basics are described, but as you rightly noted above, you need English, you can’t do without it.