"The viewWillAppear function belongs to the UIViewController class. So for our ViewController, which subclasses UIViewController, we'll want to override it."
I have no idea of what the instructor's sentence means. I'm a beginner. Can someone please explain to me in beginner-friendly speech? I'm completely confused. Thank you.
Okay, nevermind, a friend explained this to me. Thank you so much everyone. Please answer anyway in case someone else has the same question. Thank you.
I would add that study of the view-controller lifecycle would benefit any newcomer to iOS development, at least until SwiftUI attains world domination. My favorite lifecycle method is didReceiveMemoryWarning().