NEW: Subscribe to Hacking with Swift+ and accelerate your learning! >>

How to fix “Initializer 'init(_:rowContent:)' requires that ‘SomeType’ conform to 'Identifiable’”

Paul Hudson    @twostraws   

Updated for Xcode 12.0

There are three common reasons this error occurs, and all are relatively easy to fix.

The first reason is using a List or ForEach like this:

ForEach(1 ... 10) {

SwiftUI supports the half-open range operator, ..<, but not the closed range operator. As a result, you need to rewrite the above code to this:

ForEach(0 ..< 10) {

The second reason is using a List or ForEach on primitive types that don’t conform to the Identifiable protocol, such as an array of strings or integers. In this situation, you should use id: \.self as the second parameter to your List or ForEach, like this:

ForEach(stringArray, id: \.self) {

That tells SwiftUI that each value in the array is unique, and so can be used to identify each item in the loop.

The final reason its happens is if you’re looping over an array of custom structs that don’t conform to Identifiable. Here you should add either add a conformance to that protocol (which means adding an id property that is unique), or use id: \.someUniquePropertyName as the second parameter to your List or ForEach, which uses that property instead of the ID.

For example:

struct User: Identifiable {
    var id = UUID()
    var username: String
}

Alternatively:

ForEach(users, id: \.username) {
Hacking with Swift is sponsored by NSSpain

SPONSORED Announcing NSSpain 2020: Remote Edition! An online, continuous conference for iOS developers. We’ll start on Thursday and finish on Friday, with talks, activities, and lots of fun for 36 hours, non-stop. Sound good? Join us!

Find out more

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

Similar solutions…

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: 4.0/5

Link copied to your pasteboard.