NEW: Master Swift design patterns with my latest book! >>

How to shuffle an array using GameplayKit

Written by Paul Hudson    @twostraws

iOS 9.0 has a built-in way to shuffle arrays thanks to GameplayKit, and it's a simple one-liner. Here's an example of creating an array of lottery balls and picking six random ones:

let lotteryBalls = [Int](1...49)
let shuffledBalls = GKRandomSource.sharedRandom().arrayByShufflingObjects(in: lotteryBalls)

That uses the system's built-in random number generator, which means it's guaranteed to be in a random state by the time it gets to you.

Available from iOS 9.0 – see Hacking with Swift tutorial 35

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Need to know Objective-C fast?

I wrote a book dedicated to teaching Objective-C to developers who already know Swift – it's the fastest way to get up to speed!

Click here to visit the Hacking with Swift store >>