To previous view controller

To pop back to the previous page you can do this:

Swift

navigationController?.popViewControllerAnimated(true)

Objective-C

[self.navigationController popViewControllerAnimated:YES];

To root view controller

To pop to the root of the navigation stack, you can do this:

Swift

navigationController?.popToRootViewControllerAnimated(true)

Objective C

[self.navigationController popToRootViewControllerAnimated:YES];