Passing data with unwind segue : <p>I created two view controllers. I created a segue from the first to the second to pass data. Now I want to pass data from the second view controller to the first one. I went through many similar questions and I'm not able to implement those as I lack the knowledge on how unwinding works. </p>

<p><strong>ViewController.swift</strong></p>

<pre><code>class ViewController: UIViewController
{   
    var dataRecieved: String?
    @IBOutlet weak var labelOne: UILabel!
    @IBAction func buttonOne(sender: UIButton)
    {
        performSegueWithIdentifier("viewNext", sender: self)
    }
    override func prepareForSegue(segue: (UIStoryboardSegue!), sender: AnyObject!)
    {

        var svc: viewControllerB = segue.destinationViewController as! viewControllerB
        svc.dataPassed = labelOne.text
    }
}
</code></pre>

<p>This will pass the data to dataPassed in view controller "viewControllerB". Say, now I want to pass some data from viewControllerB to dataRecieved in ViewController. How can I do this with only unwind segue and not by using delegate. I'm quite new to swift, would appreciate a detailed explanation.</p>
