Access Variable from Another ViewController

Well, it actually depends from your needs. If you just need to pass one piece of data from a view controller to another, you can simply define a property in your destination view controller and set it in your source view controller before performing the segue (using the func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) method).

On the other hand, if you have to pass massive data from multiple view controllers, you should consider the idea of creating a Data Model class and storing and retrieving all the information you need from there.

Refer and use the following code in your project

in FirstViewController

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) 
{
     if segue.identifier == "goNextPage"
     {
        var destinationVC = segue.destinationViewController as? SecondViewController

        destinationVC?.dataFromPreviousViewController = "Success"

     }
}

in SecondViewController

var dataFromPreviousViewController = ""  

override func viewDidLoad() 

{
    super.viewDidLoad()

    // Do any additional setup after loading the view.

    labelGetText.text = dataFromPreviousViewController

    println(labelGetText.text)

}

Important : First of all you have to set segue as Show and give identifier name as goNextPage in StoryboardSegue(whatever you want give here)

You can access variables and arrays in multiple ViewControllers through NSUserDefaults.

Saving data to NSUserDefaults:

Before we read or write data from NSUserDefaults, we must first get a reference to the NSUserDefaults class.

let prefs = NSUserDefaults.standardUserDefaults()

Once we have the reference saved to a constant, we can write data to it. You will be defining both the value and the key name to store the data.

prefs.setValue("Berlin", forKey: "userCity")

Reading data from NSUserDefaults:

Reading data is similar to writing it. Again, let’s get a reference to the NSUserDefaults class and then we can query a key for a value.

let prefs = NSUserDefaults.standardUserDefaults()
if let city = prefs.stringForKey("userCity"){
println("The user has a city defined: " + city) 
}else{ 
prefs.setValue("Berlin", forKey: "userCity")  
}