UPGRADE YOUR SKILLS: Learn advanced Swift and SwiftUI on Hacking with Swift+! >>

SwiftUI - Picker with variable data source

Forums > SwiftUI

Hello all, I am trying to make a picker (named Letters in the below example) with variable data source (lettersArray), where these data depends on selections of other picker (Numbers), I tried that through the didSet as per the below example, but it crashes. Any advice in that!

import SwiftUI

class Model: ObservableObject, Identifiable {
    var lettersArray = ["A", "B", "C"]
    var numArray = ["0", "1", "2", "3"]

    @Published var lettersIndx = 0

    @Published var numIndex = 0 {
            switch numIndex {
            case 0:
                lettersArray = ["A", "B", "C"]
            case 1:
                lettersIndx = 0
                lettersArray = ["A"]
            case 2:
                lettersIndx = 1
                lettersArray = ["B", "C"]
                lettersArray = ["A", "B", "C"]

struct ContentView: View {
    @ObservedObject var model = Model()

    var body: some View {
            Picker("Letters", selection: $model.lettersIndx) {
                ForEach(model.lettersArray.indices, id: \.self) { (index: Int) in


            Picker("Numbers", selection: $model.numIndex) {
                ForEach(model.numArray.indices, id: \.self) { (index: Int) in


struct ContentView_Previews: PreviewProvider {
    static var previews: some View {


@aliabuahmadeh I don't see the crash. It is working for me


@achuaswani ,

thanks for reply. it is crashing, at least once you move the Numbers Picker to number 2, and this message is received: Fatal error: Index out of range.


Hacking with Swift is sponsored by Superwall

SPONSORED Superwall lets you build & test paywalls without shipping updates. Run experiments, offer sales, segment users, update locked features and more at the click of button. Best part? It's FREE for up to 250 conversions / mo and the Superwall team builds out 100% custom paywalls – free of charge.

Learn More

Sponsor Hacking with Swift and reach the world's largest Swift community!

Archived topic

This topic has been closed due to inactivity, so you can't reply. Please create a new topic if you need to.

All interactions here are governed by our code of conduct.

Unknown user

You are not logged in

Log in or create account

Link copied to your pasteboard.