SwiftUI - Simple State Management

Learn about swiftUI :
https://developer.apple.com/xcode/swiftui/
https://developer.apple.com/tutorials/swiftui/

Let's do some code:

In order to use SwiftUI, we need to download XCode 11.
https://developer.apple.com/services-account/download?path=/WWDC_2019/Xcode_11_Beta/Xcode_11_Beta.xip

Steps:

1. Create simple 'SingleView Application' using xcode 11.
2. Make sure to check 'use SwiftUI'.
3. In ContentView.swift, use below code.

import SwiftUI

struct ContentView : View {
    
    @State var counter:Int = 0;
    
    var body: some View {
        VStack {
            HStack {
                Text("You counter value: ")
                    .padding(5)
                Text(String(counter))
                    .font(.largeTitle)
                    .color(.red)
                }.padding(20)
            
            HStack {
                Button(action: {
                    self.counter -= 1
                },
                       label: {
                        Text("Decrease(-)")
                })
                Spacer()
                Button(action: {
                    self.counter += 1
                },
                       label: {
                        Text("Increase(+)")
                })
            }
        }
        .padding(20)
    }
}

Here, When you declare a state, SwiftUI stores it for you and manages the state’s connections to its view. When the state updates, the view invalidates its appearance and updates itself.

That's all

You can also look into Android Jetpack Compose:
Experiment with Android Jetpack Compose