How can I save data (score) from my first viewcontroller to the second?

Question

I am creating a quiz app for ios for a big project at my school, but it is my first time making something with xcode and swift. I've run into a problem which i can't seem to figure out on my own. At the moment I am trying to keep score across multiple ViewControllers; I've tried a lot of different stuff, but it still doesn't work. I am, like I said, a noob to xcode and actually all coding.

At first i have the code for the score:

@IBOutlet weak var scoreLabel: UILabel!                                                                   
var score = 0

In my app, when someone answers the right question, the score gets 1 point (score += 1). After 4 questions of the first theme, 4 questions of a different theme, on a different ViewController are showed.

this is my code at the end of the first ViewController (MultipleChoice 2 is my second vc):

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.destination is MultipleChoice2 {
        let vc = segue.destination as? MultipleChoice2
        vc?.score = score
    }
}

Code for my second vc:

var score = Int()

@IBOutlet weak var scoreLabel: UILabel?

override func viewDidLoad() {
    super.viewDidLoad()
    scoreLabel?.text = String(score)
}

I might be doing this all wrong, but I expect the app to save the score from my first ViewController to my second, so that, when someone has score 3 points in the first vc, he still has 3 points in the second vc.

The other things that i have tried didn't work at all, but with this code i get the message Thread 1: signal SIGABRT, at class AppDelegate, after clicking on the button that sends me to the second viewcontroller.

I honestly have no clue on how to save my score to the next vc and it would be great if someone had a solution to this..

Possible duplicate of [Passing Data between View Controllers](https://stackoverflow.com/questions/5210535/passing-data-between-view-controllers) — Tamás Sengel, Dec 12 '17 at 13:12

score 0 · Answer 1 · answered Dec 12 '17 at 13:22

0

Check if all the outlets are connected. After that check whether segue is connected or not.

Change

var score = Int()

to

var score: Int = 0

in secondVC and try again.

answered Dec 12 '17 at 13:22

Rahul Dasgupta

894
6
18

score 0 · Answer 2 · answered Dec 12 '17 at 14:23

Try following and let me know if you face any trouble getting it working : First of all change declaration of score variable in secondVC to

var score : Int = 0

then in prepare for segue method you can try these : first set segue identifier from storyboard as it is more convenient to use : then you can check if we are in proper condition by

if segue.identifier == "showSecondVC" {
    let vc = segue.destination as! MultipleChoice2
    vc.score = score
}

Also use breakpoint to check whether everything is executing properly One more thing is you can set label text by using following code also :

scoreLabel?.text = "\(score)"

score 0 · Answer 3 · answered Dec 12 '17 at 19:08

Change var score = Int() to var score: Int? in second view controller.
Set segue identifier to second view controller in storyboard.

Modify segue method as below in first view controller

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showSecondVC" {
        let vc = segue.destination as! MultipleChoice2
        vc.score? = score
    }
}

How can I save data (score) from my first viewcontroller to the second?

3 Answers3