NEW: Start my new Ultimate Portfolio App course with a free Hacking with Swift+ trial! >>

How to generate a random number

Swift version: 5.2

Paul Hudson    @twostraws   

You can generate random numbers by calling the random() method on whatever numeric type you’re using, providing the range you want to work with. For example, this generates a random number in the range 1 through 5, inclusive on both sides:

let randomInt = Int.random(in: 1...5)

Similar methods exist for Double, Float, and CGFloat:

let randomDouble = Double.random(in: 1...100)
let randomFloat = Float.random(in: 1..<10)
let randomCGFloat = CGFloat.random(in: 1...1000)

There’s also one for booleans, generating true or false randomly:

let randomBool = Bool.random()

Checking a random boolean is effectively the same as checking Int.random(in: 0...1) == 1, but it helps clarify your intent.

Hacking with Swift is sponsored by Fernando Olivares

SPONSORED Would you describe yourself as knowledgeable, but struggling when you have to come up with your own code? Fernando Olivares has a new book containing iOS rules you can immediately apply to your coding habits to see dramatic improvements, while also teaching applied programming fundamentals seen in refactored code from published apps.

Try the book!

Sponsor Hacking with Swift and reach the world's largest Swift community!

Available from iOS 8.0 – see Hacking with Swift tutorial 35

Similar solutions…

About the Swift Knowledge Base

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

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.4/5

 
Unknown user

You are not logged in

Log in or create account
 

Link copied to your pasteboard.