My Tip Calculator doesn't work if I get these erors?

Question

I'm new coding with Swift and I'm doing YouTube's beginner projects to learn, and currently I'm building a tip calculator, but I have the next errors:

• Non-constant range: argument must be an integer literal

• Instance member 'tipPercentages' cannot be used on type 'ContentView'; did you mean to use a value of this type instead?

And this is my code:

import SwiftUI

struct ContentView: View {

@State private var checkAmount = ""
@State private var numberPeople = ""
@State private var tipPercentage = 2

let tipPercentages = [10, 15, 20, 25, 0]

var totalPerPerson: Double {
    
    
    let peopleCount = Double(numberPeople) ?? 0
    let tipSelection = Double(tipPercentages[tipPercentage])
    let orderAmount = Double(checkAmount) ?? 0
    
    let tipVaule = (orderAmount / 100) * tipSelection
    let grandTotal = orderAmount + tipVaule
    let amountPerPerson = grandTotal / peopleCount
    
    return amountPerPerson
    
}


var totalAmount: Double {
    let tipSelection = Double(tipPercentages[tipPercentage])
    let orderAmount = Double(checkAmount) ?? 0
    
    let tipValue = (orderAmount / 100 ) * tipSelection
    let grandTotal = orderAmount + tipValue
    
    return grandTotal
    
    
}

var body: some View {
    
    
    NavigationView {
        Form{
            Section{
                TextField("Amount", text: $checkAmount)
                    .keyboardType(.decimalPad)
                
                TextField("Number of people:", text: $numberPeople).keyboardType(.numberPad)
            }
            
            Section(header: Text("How much tip do you want to leave")) {
                
                
                Picker("Tip Percentage", selection: $tipPercentage){
                    
                    ForEach(0..<tipPercentages.count){
                        Text("\(Self.tipPercentages[$0])%")
                        
                    }
                    
                }
                .pickerStyle(SegmentedPickerStyle(])
                
            }
                    
                    Section(header: Text("Amount per person")){
                    
                    
                    Text("$\(totalPerPerson, specifier: "$.2f")")

                }
                    
                    Section(header: Text ("Total amount of the check")){
                    
                    Text("$\(totalAmount, specifier: "N.2f")")
                        .foregroundColor(tipPercentage == 4 ? .red : .primary)
                    
                }
                    
                        .navigationBarTitle("SplitTip")
            
        }
    }
    
}
}

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

Answer 1

This is what i found at first glance. Your code is full of typos.

First use this constructor to itterate over the array:

ForEach(tipPercentages, id: \.self){ percentage in
          Text("\(percentage)%")
}

and change this:

.pickerStyle(SegmentedPickerStyle())

edit:

The reason for the fatal error is because we changed the selection. Until now you saved the index of the array in tipPercentage. Now you save the percentage itself. So you do not longer need to refer to the index.

Remove this:

let tipSelection = Double(tipPercentages[tipPercentage])

Change this:

let tipValue = orderAmount * tipPercentage / 100 //No need for brackets here :)