Do I need to understand old versions of libraries that have deprecated functions?

Question

Android

I wanted to study the view pager, but when I created the fragment pager adapter, it was crossed out, and I googled and found viewpager 2, it works a little differently, and so I wondered if the simple view pager should be studied, or has it already sunk in the fly? If some functions are crossed out, they still work.

Answer 1

1) to know how they work - it is desirable, you will still meet outdated code in life
2) to use such libraries and modules in new projects and new works - it is highly undesirable