Swift (Mobile Dev) 5

Question 1

What does the `Codable` typealias combine in Swift?

Accepted Answer

Encodable and Decodable

Answer

`Codable` is a type alias for `Encodable & Decodable`, enabling both JSON serialization and deserialization.

Question 2

In Swift's structured concurrency, what is the role of a `TaskGroup`?

Accepted Answer

It creates child tasks that run concurrently and collects their results

Answer

TaskGroup lets you spawn a dynamic number of child tasks that run concurrently and then gather their results in order.

Question 3

Which Xcode build setting controls the minimum iOS version your app can run on?

Accepted Answer

IPHONEOS_DEPLOYMENT_TARGET

Answer

IPHONEOS_DEPLOYMENT_TARGET sets the lowest iOS version the binary supports, affecting which APIs are available.

Question 4

What is a Swift `protocol` with an associated type commonly used for?

Accepted Answer

Creating generic abstractions that work with multiple conforming types

Answer

Associated types make protocols generic, letting conforming types specify the concrete type while the protocol defines the interface.

Question 5

Which method on `UserDefaults` persists a String value for a given key?

Accepted Answer

set(_:forKey:)

Answer

UserDefaults.standard.set(_:forKey:) stores the value persistently in the app's defaults database.

Swift Practice Test