title: Passing data in transitionFromViewController
body: <p>I'm using transitionFromViewController to switch between two view controllers using a segmented control.</p>
  
  <p>Here's my code:</p>
  
  <pre><code>    @IBAction func valueChanged(sender: AnyObject) {
  
      var newController = storyboard?.instantiateViewControllerWithIdentifier(viewControllerIdentifiers[sender.selectedSegmentIndex]) as! UIViewController
      let oldController = childViewControllers.last as! UIViewController
  
  
  
      oldController.willMoveToParentViewController(nil)
      addChildViewController(newController)
      newController.view.frame = oldController.view.frame
  
      if viewControllerIdentifiers[sender.selectedSegmentIndex] == "first" {
  
          let vc = newController as! userProfileViewController
          vc.userToShow = self.userToShow
  
      }
  
      transitionFromViewController(oldController, toViewController: newController, duration: 0.25, options: .TransitionCrossDissolve, animations:{ () -&gt; Void in
          // nothing needed here
  
  
  
  
          }, completion: { (finished) -&gt; Void in
              oldController.removeFromParentViewController()
  
              newController.didMoveToParentViewController(self)
  
      })
  
  }
  </code></pre>
  
  <p>is it possible to pass data to the childViewControllers, from the Parent?</p>