Add and remove childviewcontroller in swift

addremovechildviewcontroller.swift

// in parent view controller
@IBAction func showChildViewController(sender: AnyObject) {
  let testController = self.storyboard!.instantiateViewControllerWithIdentifier("Test") as! Test
  self.addChildViewController(testController)
  self.view.addSubview(testController.view)
  testController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)
  testController.didMoveToParentViewController(self)
}

// in child view controller
@IBAction func dismissTapped(sender: AnyObject) {
  self.view.removeFromSuperview()
  self.removeFromParentViewController()
}