onAppear and onDisappear Patterns

Use lifecycle hooks with control, not guesswork.

Add onAppear to start a simple timer.

Repeat with onDisappear to stop it.

Observe how navigation affects the calls.

This drill keeps lifecycle side effects clean.

Knowing when these fire prevents bugs.

Repetition makes the behavior obvious.

Cancel timers and tasks on disappear to prevent leaks.

Repeat in nested navigation to see call order.

Try the repetition loop

Pick a SwiftUI concept and write it 50 times. Feel the pattern lock in.