Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trialJustin Comstock
101 PointsIt seems cumbersome to have to list out each and every enum case like in the video.
Is there a better way to get the cases in the array.
https://teamtreehouse.com/library/concrete-types-and-property-lists-2
2 Answers
Michael Hulet
47,913 PointsWhen this video was recorded, that was the only way. You're right that this is super cumbersome and not very DRY. However, in Swift 4.2 (which came out in October, alongside iOS 12 and Xcode 10), the compiler can synthesize conformance to a new protocol called CaseIterable
. By marking your enum
as conforming to CaseIterable
, it automatically gets a static
property called allCases
, which is an array containing all the cases in your enum
. You can mark your conformance like this:
enum VendingSelection: CaseIterable { // Notice the conformance up here
case soda
case dietSoda
case chips
case cookie
case sandwich
case wrap
case candyBar
case popTart
case water
case fruitJuice
case sportsDrink
case gum
}
Later on when you need all the case
s in the enum
, you can get it like this:
let selection = VendingSelection.allCases
Justin Comstock
101 PointsThanks, I found it out when I asked but I put it inside an array by accident so it didn't work. "[VendingSelection.allCases]" was wrong.