Swift (Mobile Dev) 4

Question 1

What Swift feature allows a type to provide a custom implementation of an operator like `+`?

Accepted Answer

Operator overloading

Answer

Operator overloading lets you define or redefine how standard operators behave for custom types.

Question 2

In UIKit's view lifecycle, which method is called when a view controller's root view is added to the window hierarchy?

Accepted Answer

viewDidAppear

Answer

viewDidAppear is called after the view has been fully added to the screen and any animations have completed.

Question 3

Which Swift keyword defines a stored value that can never change after initialization?

Accepted Answer

let

Answer

`let` declares a constant, whose value is set once at initialization and cannot be reassigned.

Question 4

How does `weak` differ from `unowned` in Swift memory management?

Accepted Answer

weak becomes nil when the object deallocates; unowned does not

Answer

`weak` references become nil automatically when the referenced object is deallocated, while `unowned` crashes if accessed after deallocation.

Question 5

Which App Store Connect capability must be enabled for an iOS app to receive push notifications?

Accepted Answer

Push Notifications entitlement

Answer

The Push Notifications entitlement (and its corresponding APNs certificate or key) must be configured to allow an app to receive remote notifications.

Swift Practice Test

Swift Practice Test

Swift (Mobile Dev) 4