Access array data from another view controller - ios

Question

In TerningspilletSpillereViewController I have an array that looks like this:
var mineSpillere = ["1SP", "2SP", "3SP"]
and this under:
func assignArray() {
let obj = TerningspilletViewController()
obj.mineSpillere2 = self.mineSpillere
}
In my other UIViewController (TerningspilletViewController) I have this
var mineSpillere2 = [String]()
I want to generate a random (1SP, 2SP or 3SP) on button click like this from a function:
func generateNumber() {
let array = aBB
let randomIndex = Int(arc4random_uniform(UInt32(array.count)))
randomLabel.text = (array[randomIndex])
}
But this gives me the following error:
fatal error: Array index out of range.
I this line randomLabel.text = (array[randomIndex])
Why is that?

Answer 1

See this example and update for your usage. I'm not quite understanding your naming but this is how you can get the data from a different view controller (that is initialized with the data).
First View Controller:
import UIKit
class ViewController: UIViewController {
var arrayWithoutData = [String]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
assignArray()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func assignArray() {
let otherVC = NextViewController()
arrayWithoutData = otherVC.mineSpillere
println(arrayWithoutData)
}
}
Second View Controller:
import UIKit
class NextViewController: UIViewController {
var mineSpillere = ["1SP","2SP","3SP"]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}

Answer 2

That error could occur for two reasons:
The array length changes between the call to array.count and the array access. This could only happen if you assign or modify the array from another thread
The array is empty, in which case arc4random_uniform can never produce a number 0<=X<0 (and whatever it returns will trigger an index-out-of-bounds exception).
So if you are not using multiple threads, check if the array is empty.