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.
BUILD THE ULTIMATE PORTFOLIO APP Most Swift tutorials help you solve one specific problem, but in my Ultimate Portfolio App series I show you how to get all the best practices into a single app: architecture, testing, performance, accessibility, localization, project organization, and so much more, all while building a SwiftUI app that works on iOS, macOS and watchOS.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Other changes in Swift 4.0…
- Encoding and decoding data using Codable
- Multi-line string literals
- Improved keypaths for key-value coding
- Improved dictionary functionality
- Strings are collections again
Download all Swift 4.0 changes as a playground Link to Swift 4.0 changes
