// rootViewControllerに戻る navigationController?.popToViewController(navigationController!.viewControllers[0], animated: true) // または navigationController?.popToRootViewControllerAnimated(true) // rootViewControllerの1つ先のViewControllerに戻る navigationController?.popToViewController(navigationController!.viewControllers[1], animated: true) // rootViewControllerの2つ先のViewControllerに戻る navigationController