Hello,

I'm completely new to programming and have never done this before.

After doing project 2 of 100 days of SwiftUI, I thought I would try to add some of my own code before moving on to the next project. I managed to add a player name, but the app crashes after question 9 of the game when I play it again & I am not sure why.

I see a "Thread 1: fatal error: index out of range" error on line 53: Image(countries[number]).

Why does this error occur during a new game?

Here is my code:

static let allCountries = ["Estonia", "France", "Germany", "Ireland", "Italy", "Monaco", "Nigeria", "Poland", "Spain", "UK", "Ukraine", "US"]
@State private var countries = allCountries.shuffled()
@State private var correctAnswer = Int.random(in: 0...2)
@State private var nameGiven = true
@State private var playerName = ""

@State private var showingResults = false
@State private var showingScore = false
@State private var scoreTitle = ""
@State private var score = 0
@State private var QuestionCounter = 1
var body: some View {
    ZStack {
        RadialGradient(stops: [
            .init(color: Color(red: 0.1, green: 0.2, blue: 0.45), location: 0.3),
            .init(color: Color(red: 0.76, green: 0.15, blue: 0.26), location: 0.3)
        ], center: .top, startRadius: 200, endRadius: 700)

        .ignoresSafeArea()

        VStack {
            Spacer()

            Text("Guess the flag")
                .font(.largeTitle.weight(.bold))
                .foregroundStyle(.white)
            VStack (spacing: 15) {

                VStack {
                    Text("Tap the flag of")
                        .foregroundStyle(.secondary)
                        .font(.subheadline.weight(.heavy))

                    Text(countries[correctAnswer])
                        .font(.largeTitle.weight(.semibold))

                }
                ForEach(0..<3){ number in
                    Button {
                        flagTapped(number)
                    } label: {
                        Image(countries[number])
                            .clipShape(.capsule)
                            .shadow(radius: 5)
                    }
                }
            }
            .frame(maxWidth: .infinity)
            .padding(.vertical, 20)
            .background(.regularMaterial)
            .clipShape(.rect(cornerRadius: 20))

            Spacer()
            Spacer()

            Text ("\(playerName)'s Score: \(score) / 10")
                .foregroundStyle(.white)
                .font(.title.bold())
        }
    }
    .alert(scoreTitle, isPresented: $showingScore) {
        Button("Continue", action: askQuestion)
    } message: {
        Text("Your score is \(score) / 10")
    }
    .alert("Game over!", isPresented: $showingResults) {
        Button("Finish", action: restartGame)
    } message: {
        Text("Your final score was \(score) / 10")
    }

    .alert("Enter your name", isPresented: $nameGiven) {
        TextField("Name", text: $playerName)
        Text("Play")
    }
}

func flagTapped(_ number: Int) {
    if number == correctAnswer {
        scoreTitle = "Correct, \(playerName)!"
        score += 1
    } else {
        let needsThe = ["UK", "US"]
        let theirAnswer = countries[number]

        if needsThe.contains(theirAnswer) {
            scoreTitle = "Wrong, \(playerName)! that's the flag of the \(theirAnswer)"
        } else {
            scoreTitle = "Wrong, \(playerName)! That's the flag of \(theirAnswer)"
        }
    }
    if QuestionCounter == 10 {
        showingResults = true
    } else {
        showingScore = true
    }
}

func askQuestion() {
    countries.remove(at: correctAnswer)
    countries.shuffle()
    correctAnswer = Int.random(in: 0...2)
    QuestionCounter += 1
}
func restartGame() {
    QuestionCounter = 0
    score = 0
    countries = Self.allCountries
    askQuestion()
    askForPlayerName()
}
func askForPlayerName() {
    if score == 0 {
        nameGiven = true
        playerName = ""
    } else {
        nameGiven = false
    }
}
}

Thank you

Thank you @NigelGee!

Now when the game restarts, only 9 questions are asked and the final score message is always 9 / 10 for any new games played after the first one. I have tried many combinations to fix this, but I am lost and do not understand why only 9 questions are asked for new games after it restarts.

Thank you

Change your restartGame() method to be this

    func restartGame() {
        QuestionCounter = 1
        score = 0
        countries = Self.allCountries
//        askQuestion() <- Remove this
        countries.shuffle() // <- add this
        correctAnswer = Int.random(in: 0...2)  // <- add this
        askForPlayerName()
    }

Thank you so much for the help!