CODEWITHSUNDEEP
iosswiftxcodeswiftuiios-simulator
GrainsGames
GrainsGames

Reputation: 89

Simulator Freezes | SwiftUI, XCode

My result is the simulator freezing.

My expected result is for the program to add random numbers until a 7 comes up when I press the "Not Seven" button.

My goal is to complete this challenge: *Build a UI with a List and three Buttons below it.

When the first button is tapped:

Add a random integer (from 1 to 10) to the List. If the integer you added to the List wasn't a 7, then keep adding random integers (from 1 to 10) to the List until you add a 7 to the List. When the second button is tapped:

Increase all the integers shown in the List by 1 When the third button is tapped:

Clear all the numbers from the List.

This is a link to a recording of the program: https://files.fm/f/t5trf3ww3


import SwiftUI

struct ContentView: View {
    @State var numbers = [Int]()
    var body: some View {
        VStack {
            List(numbers, id: \.self) { num in
                Text(String(num))
            }
            HStack {
                Button("Not Seven") {
                    var randNumber = 0
                    randNumber = Int.random(in: 0...10)
                    repeat{
                        numbers.append(randNumber)
                    }while randNumber != 7
                }
                Button("Add 1 to All") {
                    for index in 0...numbers.count - 1 {
                        numbers[index] += 1
                    }
                }
                Button("Delete") {
                    numbers.removeAll()
                    }
                }
            }
        }
    }
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            ContentView()
            ContentView()
        }
    }
}

Upvotes: 0

Views: 171

Answers (1)

Yrb
Yrb

Reputation: 9675

You are never actually changing randNumber in your loop.

             Button("Not Seven") {
                // You initialize the variable
                 var randNumber = 0
                // You set it to a random Int
                 randNumber = Int.random(in: 0...10)
                //Then you test forever if that random Int is 7. You have a 1 in 11 chance of an infinite loop, which is why the simulator hangs.
                 repeat{
                     numbers.append(randNumber)
                }while randNumber != 7
}

Change button to:

            Button("Not Seven") {
                // No need to set it to 0 and then change it to a random Int prior to the loop.
                var randNumber = Int.random(in: 0...10)
                repeat {
                    numbers.append(randNumber)
                    //Change randNumber here to be a different random number.
                    randNumber = Int.random(in: 0...10)
                } while randNumber != 7
            }

You could probably rework the logic to not have two different `randNumber = Int.random(in: 0...10)' statements, but I have finished my coffee yet to think about that.

Upvotes: 1

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