iOS Development IOS App Developer 4

Question 1

Which SwiftUI modifier is used to respond when a view appears?

Accepted Answer

.onAppear

Answer

.onAppear runs a closure when the view is added to the view hierarchy.

Question 2

In Swift, what is an optional?

Accepted Answer

A type that may hold a value or be nil

Answer

An optional represents a value that may be present or absent (nil).

Question 3

Which framework is Apple's modern persistence solution layered on top of Core Data, introduced for SwiftUI?

Accepted Answer

SwiftData

Answer

SwiftData is Apple's macro-based persistence framework that integrates with SwiftUI.

Question 4

What is the main benefit of using dependency injection in an iOS app?

Accepted Answer

Improved testability and decoupling

Answer

Dependency injection makes components easier to test and swap by removing hard-coded dependencies.

Question 5

Which actor type in Swift concurrency guarantees its code runs on the main thread?

Accepted Answer

MainActor

Answer

@MainActor ensures the annotated code executes on the main thread, ideal for UI updates.

iOS Development Practice Test