Swift UserDefaults (2017)

Question

I'm new at Xcode and currently making an app, where you have an amount of "bananas / money", whereof you can flip a coin, and you either win 2x or lose your bet. (Just for experience)

My game is fully working, I've now just decided, that I want to save the currency for whenever the app closes and starts; using NSUserDefaults.

I've set my NSUserDefaults up, and it's working. It's displaying the currency I had the last time I closed the app, and I can only bet between 0 and my currency. - Which is great!

However, even though my full currency is displaying, and that I can bet all of my total currency, the math behind it all is still struggling. After the app closes it's putting the integer back to 0, because that's what I've declared ABOVE my viewDidLoad, when I was creating the variable.

Haven't understood? Lets say I have 30 bananas, and I'm about to bet 30 bananas. If I win, I'll have a total of 30 banans, and if I lose, I'll have -30 bananas. (The integer is for some reason set to 0)

I need a way to set the integer to my last saved; "currencySave". - And I need a way of detecting if it's the first time the app has been opened; if yes, you'll have to start with a constant integer/currency.

Code:

All of my variables are ment to be in integers.

betVar; the variable / value, that you're betting

currencyVar; the variable / value, that you're having. (Your cash)

currencySave; the name I've saved my integer into

Above viewDidLoad

let defaults = UserDefaults.standard

var currencyVar = Int(0)
var betVar = Int(0)

viewDidLoad

let currencyVar = defaults.integer(forKey: "currencySave")

labelCurrency.text = String("$ \(currencyVar)")

betVar = 0
labelBet.text = String("$ \(betVar)")

Slider, whereof you choose the bet-amount

    let currencyVar = defaults.integer(forKey: "currencySave")
    let currentValue:String = String(Int(sender.value))
    betVar = Int(currentValue)!

    labelBet.text = currentValue


    labelSlider.maximumValue = Float(currencyVar)
    labelSlider.minimumValue = Float(0)
    labelBet.text = String("$ \(currentValue)")

The math when winning a bet (It takes the money from you as you click 'bet', that means, that nothing will happen, if you're losing.)

    self.currencyVar = self.currencyVar + self.betVar*2
    self.labelBet.text = String("\(self.betVar*2)")
    self.labelBet.textColor = UIColor.green

My way of saving the integer

    defaults.set(currencyVar, forKey: "currencySave")
    defaults.synchronize()

score 0 · Accepted Answer · answered Mar 01 '17 at 15:14

0

It looks like you are creating local variables with the same name so the property is ignored.

On the top level declare

var currencyVar = 0 // the compiler infer the Int type.

In viewDidLoad delete let

self.currencyVar = defaults.integer(forKey: "currencySave")

In Slider, whereof you ... use only the instance variable, delete the entire line

~~let currencyVar = defaults.integer(forKey: "currencySave")~~

and add self (although it's not required) to indicate the property.

labelSlider.maximumValue = Float(self.currencyVar)

answered Mar 01 '17 at 15:14

vadian

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THANKS! Thanks a lot for your fast reply. It really helped me out, and it's now totally working. Now that I have an experienced programmer on hand. What if I want to make some kind of a statistic system? Where I can see bets placed, best won and stuff. I'm thinking of making an unique Userdefaults-keyword, that gonna get added by one for each time; a variable? - You'll get my reputation, if I can find some way of honoring you. – Kasper Weber Andersen Mar 01 '17 at 15:56
For a statistics system which collects a bunch of data I'd prefer Core Data. – vadian Mar 01 '17 at 16:02
It's only those 3-4 statistics and not ment to become a graph or something. But if you say so, I'll google for Core Data, thanks for your answer! – Kasper Weber Andersen Mar 01 '17 at 16:03

Swift UserDefaults (2017)

1 Answers1