swiftui - lazy stacks versus lists

Notes from Ray Wenderlich’s Swift UI - Layout Interfaces

Hacking with Swift has a great article as well

Lists

Similar to UITableView and UITableViewCell in UIKit
A specialized version of lazy v stacks
They are more common to use
They have built in functionality, such as swiping to delete, reordering, and styling (similar to table views)
Lazy loads the data, but the data is loaded up front

struct ContentView: View {
    var body: some View {
        List {
            let formatter: DateFormatter = {
                let formatter = DateFormatter()
                formatter.timeStyle = .medium
                return formatter
            } ()
            ForEach(1...10000, id: \.self) { item in
                Text(
                    formatter.string(from: Date())
                )
            }
        }
    }
}

Lazy Stacks

Lazy loads the data, but the data is loaded just in time (aka when it comes into view)
Use Lazy Stacks when you notice a performance issue

struct ContentView: View {
    var body: some View {
        ScrollView {
            LazyVStack {
                let formatter: DateFormatter = {
                    let formatter = DateFormatter()
                    formatter.timeStyle = .medium
                    return formatter
                } ()
                ForEach(1...10000, id: \.self){ item in
                    Text(
                        formatter.string(from: Date())
                    )
                }
            }
        }
    }
}