jetpack vs SwiftUi

flutter_ui.dart

class MyApp extends State<MyHomePage> {
  int count = 0;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Column(children: <Widget>[
        Text('count $count',),
        FlatButton(child: Text("Increment",), onPressed: () { setState(() { count++; });}),
        FlatButton(child: Text("Decrement",), onPressed: () { setState(() { count--; });}),
    ]));
  }
}

jetpack.kt

@Composable
fun AppBody() {
    val count = +state { 0 }

    Center {
        Column {
            Text("count: ${count.value}")
            Button("Increment", onClick = { count.value++ })
            Button("Decrement", onClick = { count.value-- })
        }
    }
}

swift_ui_declarative.swift

struct AppBody : View {
    @State var count = 0
    
    var body: some View {
        VStack {
            Text("count: \(count)")
            Button("Increment") { self.count += 1 }
            Button("Decrement") { self.count -= 1 }
        }
    }
}