How can I get the native screen resolution sdl2.0

Hello! First time posting here.
So I searched how to get the native screen resolution and only found answer for sdl1.2 that can’t work with sdl2 and different way that doesn’t involve SDL library. Is there any way to do it with sdl2.0 ?

thank you in advance

Depends on what you want.

Resolution of the entire desktop:

Resolution of a specific monitor: