Which method of interface loading is called before the other: viewDidLoad or viewDidAppear?

The viewDidLoad method is called first when the controller loads its interface into memory. This happens once in the controller's lifecycle, usually right after loading from a storyboard or nib.

The viewDidAppear method is called later, when the view has already been added to the screen and is visible to the user. This method can be called multiple times, for example, each time the screen appears.

In summary:

• First, viewDidLoad is called — setting up the interface and initializing.
• Then, viewDidAppear — when the interface is already displayed and animations can be started or data can be updated.