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

Paul Hudson    @twostraws   

Updated for Xcode 13.0 beta 2

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 {
    let id = UUID()
    let username: String
}

If you were looping over an array of those User objects and wanted to identify them uniquely by their username, you’d use this:

ForEach(users, id: \.username) {
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