Fatal Error creating Array - ios

Question

This is the code I have. Basically when the user first chooses the quality of the dinning whether it is fine (20%), casual (15%), or a bar (11%). From there the user will then be asked on a 1-5 scale about the food quality, service, etc. Depending what number they choose, for example if the fine dinning was a 5/5 then it will ad 4% to the already 20 percent (each number will have a selected value to add to the tip). Can anyone figure out what's going on? Or if there is a better way about doing it.
import UIKit
#IBDesignable
class ViewController: UIViewController {
#IBOutlet weak var billTotal: UITextField!
var diningValue: Double = 0.0
#IBAction func toggleFineDining(sender: UIButton) {
sender.highlighted = sender.selected
if sender.selected == true{
diningValue = 0.20
}
}
#IBAction func toggleCasualDining(sender: UIButton) {
sender.highlighted = sender.selected
if sender.selected == true{
diningValue = 0.15
}
}
#IBAction func toggleBartender(sender: UIButton) {
sender.highlighted = sender.selected
if sender.selected == true{
diningValue = 0.11
}
}
#IBOutlet weak var service: UITextField!
#IBOutlet weak var friendliness: UITextField!
#IBOutlet weak var foodQuality: UITextField!
#IBOutlet weak var atmosphere: UITextField!
#IBOutlet weak var overall: UITextField!
#IBOutlet weak var recommend: UISwitch!
#IBOutlet weak var total: UILabel!
func totalBill(inputArray: [Double], value: Double, recommend: Bool)->Double{
var array: [Double] = []
let total = inputArray[0]
for var i = 1; i < inputArray.count; ++i {
array.append(inputArray[i] * 0.01)
}
let sum = array.reduce(0, combine: +)
var totalTip = Double()
if recommend == true{
totalTip = sum + value
} else {
if sum < 0.15 {
totalTip = 0.15
} else {
totalTip = sum + value
}
}
let tipValue = totalTip * total
return total + tipValue
}
#IBAction func calcTotal(sender: AnyObject) {
var valueList = [String(service.text), String(friendliness.text), String(foodQuality.text), String(atmosphere.text), String(overall.text)]
let list = doubleArray(valueList)
print(list)
let initialTotal = Double(billTotal.text!)
let total_bill = totalBill(list, value: diningValue, recommend: recommend.selected)
print("Total: ", total_bill)
print(String(format: "%.3f", Double(total_bill)))
total.text = "$" + String(format: "%.2f", Double(total_bill))
//diningValue = diningValue
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
func doubleArray(list: [String])->[Double]{
var doubledList: [Double] = []
for element in 0...list.count{
let doubledElement = Double(list[element])
doubledList.append(doubledElement!)
}
return doubledList
}

Answer 1

Your issue is in the last function:
func doubleArray(list: [String])->[Double]{
var doubledList: [Double] = []
for element in 0...list.count{
let doubledElement = Double(list[element])
doubledList.append(doubledElement!)
}
return doubledList
}
Your loop is looping from 0 to list.count and it crashes at list[element] when element is list.count (Out of Index)
You need to change from 0...list.count to 0..<list.count:
func doubleArray(list: [String])->[Double]{
var doubledList: [Double] = []
for element in 0..<list.count{
let doubledElement = Double(list[element])
doubledList.append(doubledElement!)
}
return doubledList
}
I would recommend you to do it in swifty way:
func doubleArray(list: [String])->[Double]{
var doubledList: [Double] = []
for element in list {
doubledList.append(Double(element) ?? 0.0)
}
return doubledList
}
A shorter version using map function:
func doubleArray(list: [String])->[Double]{
return list.map( { Double($0) ?? 0.0 })
}