List vs LazyVStack

ContentView.swift

//
//  ContentView.swift
//  ListVsLazyVStack
//
//  Created by Alexander Kraev on 05.01.2022.
//

import SwiftUI

@main
struct ListVsLazyVStackApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

struct SampleRow: View {
    let id: Int

    let emojiArray = ["👍🏻", "🤷🏼‍♂️", "🧐", "😃", "👨🏻‍💻"]
    var body: some View {
        VStack {
            Text("Row \(id)")
            Text("Random emoji: \( emojiArray.randomElement() ?? "😔" )")
            RatingView(rating: Int.random(in: 0..<5))
        }
        .frame(height: 100)
        .padding()
    }

    init(id: Int) {
        print("Loading row \(id)")
        self.id = id
    }
}

struct RatingView: View {
    var rating: Int
    var body: some View {
        HStack {
            ForEach(0..<5) { starIndex in
                StarImage(isFilled: rating > starIndex)
            }
        }
    }
}

struct StarImage: View {
    var isFilled: Bool
    
    var body: some View {
        Image(systemName: "star.fill").foregroundColor( isFilled ? .yellow : .gray)
    }
}

struct ContentView: View {
    var body: some View {
        Text("LazyVStack iOS 14").font(.largeTitle)
        ScrollView {
            LazyVStack {
                ForEach(1...100, id: \.self, content: SampleRow.init)
            }
        }
        /*
         // uncomment this for test List rendering on iOS 14
        Text("List iOS 14").font(.largeTitle)
        List {
            ForEach(1...100, id: \.self, content: SampleRow.init)
        }
         */
    }
}

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