Hi,

I'm working on the 100 days of Swiftui and because I'm having trouble grasping some of the content I've learned I started doodling with a simple app to test what I've learned. But I'm having trouble with the concept of updating a state variable in multiple views. To demonstrate my problem I made a simple example.

InsertView.swift

import SwiftUI

struct InsertView: View {

    @State private var number: Int = 0

    var body: some View {
        Button("Add to number") {
            number += 1
        }

        Text("Initial: \(number)")
    }
}

#Preview {
    InsertView()
}

ContentView.swift

import SwiftUI

struct ContentView: View {

    @State var number: Int

    var body: some View {
        InsertView()
        Text("Controle: \(number)")
    }
}

#Preview {
    ContentView(number: 0)
}

In this example both numbers should be the same when pressing the button and incrementing the number. I hope someone can help me understand this and point me in the right direction.

Thank you @Hatsushira, it works in my testcase.

InsertView.swift

import SwiftUI

struct InsertView: View {

    @Binding var number: Int

    var body: some View {
        Button("Add to number") {
            number += 1
        }

        Text("Initial: \(number)")
    }
}

#Preview {
    @State var number = 0
    return InsertView(number: $number)
}

ContentView.swift

import SwiftUI

struct ContentView: View {

    @State var number: Int

    var body: some View {
        InsertView(number: $number)
        Text("Controle: \(number)")
    }
}

#Preview {
    @State var number = 0
    return ContentView(number: number)
}

Hopefully I can implement this in the project.

You're welcome.

In ContentView you can give an initial value to number if you like.