SwiftUIでButtonを押すたびにテキストを変更・入れ替える処理

import SwiftUI

struct ContentView: View {
    @State var message = "Hello"
    @State var buttonState = false
    
    var body: some View {
        VStack {
            Image(systemName: "globe")
                .imageScale(.large)
                .foregroundColor(.accentColor)
            
            Text(message)
            Button("Toggle") {
                buttonState = !buttonState
                message = buttonState ? "Hello world !" : "Change the world !"
            }
        }
        .padding()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}