Passing Data through Segue

The first thing you need to do is attach a segue from one view controller to another. Do NOT attach a segue from a button to a view controller or this will not work.

 
class FirstVC: UIViewController {
    
    @IBAction func ToSecondVC(sender: AnyObject) {
        let data = "Pass this to next view controller"
        performSegueWithIdentifier("ToSecondVCSegue", sender: data)
    }
    
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        let secondVc = segue.destinationViewController as! SecondVC
        secondVc.data = sender as? String
    }
}

class SecondVC: UIViewController {

    var data: String?
    
    @IBOutlet weak var dataLabel: UILabel!
    
    override func viewDidLoad() {
        dataLabel.text = data
    }
}
 

(Swift 2.2)