Any example of GUI in c#?

Unity Engine
1

I’m looking for some samples of implementing the GUI in C#. Any example or link to an example would be appreciated.

2

Its exactly the same as in JS.
The difference is that C# does not hide away the fact that you create new objects everywhere, thus you have new Rect(…) instead of Rect(…) in them and its void OnGUI() instead of function OnGUI()