Looking to understand the iOS UIViewController lifecycle

Question

Could you explain me the correct manner to manage the UIViewController lifecycle?

In particular, I would like to know how to use Initialize

Answer 1

As per Apple's doc — Start Developing iOS Apps (Swift) — Work with View Controllers — Understand the View Controller Lifecycle

viewDidLoad()—Called when the view controller’s content view (the top of its view hierarchy) is created and loaded from a storyboard. … Use this method to perform any additional setup required by your view controller.

viewWillAppear()—Called just before the view controller’s content view is added to the app’s view hierarchy. Use this method to trigger any operations that need to occur before the content view is presented onscreen

viewDidAppear()—Called just after the view controller’s content view has been added to the app’s view hierarchy. Use this method to trigger any operations that need to occur as soon as the view is presented onscreen, such as fetching data or showing an animation.

viewWillDisappear()—Called just before the view controller’s content view is removed from the app’s view hierarchy. Use this method to perform cleanup tasks like committing changes or resigning the first responder status.

viewDidDisappear()—Called just after the view controller’s content view has been removed from the app’s view hierarchy. Use this method to perform additional teardown activities.