NEW: My new book Pro SwiftUI is out now – level up your SwiftUI skills today! >>

One-sided ranges

Available from Swift 4.0

Paul Hudson      @twostraws

Last but not least, Swift 4 introduced Python-like one-sided collection slicing, where the missing side is automatically inferred to be the start or end of the collection. This has no effect on existing code because it's a new use for the existing operator, so you don't need to worry about potential breakage.

Here's an example:

let characters = ["Dr Horrible", "Captain Hammer", "Penny", "Bad Horse", "Moist"]
let bigParts = characters[..<3]
let smallParts = characters[3...]
print(bigParts)
print(smallParts)

That code will print out ["Dr Horrible", "Captain Hammer", "Penny"] then ["Bad Horse", "Moist"].

For more information see the Swift Evolution proposal for this new feature.

Hacking with Swift is sponsored by Play

SPONSORED Play is the first native iOS design tool created for designers and engineers. You can install Play for iOS and iPad today and sign up to check out the Beta of our macOS app with SwiftUI code export. We're also hiring engineers!

Click to learn more about Play!

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

Other changes in Swift 4.0…

Download all Swift 4.0 changes as a playground Link to Swift 4.0 changes

Browse changes in all Swift versions

 
Unknown user

You are not logged in

Log in or create account
 

Link copied to your pasteboard.