General topic questions
View controller lifecycle
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Free section · general topics & algorithms
Walk through the UIViewController lifecycle and where you would load data, configure UI, and clean up observers.
Reveal model answer
loadView → viewDidLoad (one-time setup) → viewWillAppear → viewIsAppearing → viewDidAppear → viewWillDisappear → viewDidDisappear → deinit. Load remote data after first appear or via a dedicated loader; remove NotificationCenter/KVO observers in deinit or viewDidDisappear depending on scope; cancel in-flight tasks when the screen disappears if results are no longer needed.