Swift version: 5.6
Sets and arrays both store objects of your choosing, but they have four important differences:
As a result, you should use a set rather than an array if all the following criteria are true:
Hashabletypes, either your own or one of Swift’s built-in types likes strings and integers. Sets use hash values for fast look up of items.
You can switch between an array and a set simply enough:
let array = [1, 2, 3] let set = Set(array) let array2 = Array(set)
contains() on a set takes the same amount of time if you have one item as it does if you have one thousand items – it’s called an O(1) operation.
SPONSORED Let’s face it, SwiftUI previews are limited, slow, and painful. Judo takes a different approach to building visually—think Interface Builder for SwiftUI. Build your interface in a completely visual canvas, then drag and drop into your Xcode project and wire up button clicks to custom code. Download the Mac App and start your free trial today!
Available from iOS – learn more in my book Pro Swift
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Link copied to your pasteboard.