レベルの高い SwiftUI 面接（仮）

ContentView.swift

//
// 元ツイート:
// https://twitter.com/tobi462/status/1529687893811556354?s=20&t=LUmtHH5wXylCFqTQpfgyVg
//
// ボーナス問題:
// https://twitter.com/tobi462/status/1529727505313124353?s=20&t=LUmtHH5wXylCFqTQpfgyVg
//

struct ContentView: View {
    @State var text: String = "🍎"
    @State var message: String = "Hello"
    @State var xs: [Int] = [0, 1, 2, 3]

    var body: some View {
        let _ = Self._printChanges() // ①
        VStack {
            Button("Touch") {
                text = "🍊" // ②
                message = "Swift"
            }
            Text(text)
            Text(message)
        }
        .onChange(of: text) { _ in
            let x = xs.removeFirst() // ③
            text = "🍌 \(x)"
        }
    }
}