In ios, when AViewController launches another ViewContoller (BViewController), AViewController's preparedForSegue() will get calls and " segue.destinationViewController" will be a reference to BViewController.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
segue.destinationViewController
}
My question is if BViewController 'Back' to AViewController, which method of AViewController will get call, and AViewController knows it comes from BViewController?