bobleesj

override func viewDidDisappear(_ animated: Bool) {
  super.viewDidDisappear(true)
  NotificationCenter.default.removeObserver(self)
}

bobleesj

func catchNotification(notification:Notification) -> Void {
  guard let name = notification.userInfo!["name"] else { return }
 
  FirstVCLabel.text = "My name, \(name) has been passed! 😄"
}

bobleesj

NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: myNotificationKey), 
                                       object: nil, 
                                       queue: nil, 
                                       using:catchNotification)

bobleesj

import UIKit

 class FirstVC: UIViewController {
   @IBOutlet weak var FirstVCLabel: UILabel!
   
   override func viewDidLoad() {
     super.viewDidLoad()
     NotificationCenter.default.addObserver(self, 
                                            selector: #selector(doSomethingAfterNotified),
                                            name: NSNotification.Name(rawValue: myNotificationKey), 

bobleesj

@IBAction func tabToNotifyBack(_ sender: UIButton) {
  NotificationCenter.default.post(name: Notification.Name(rawValue: myNotificationKey), object: self)
  
  secondVCLabel.text = "Notification Completed!😜"
}

bobleesj

class SecondVC: UIViewController {
  @IBOutlet weak var secondVCLabel: UILabel!
  
  override func viewDidLoad() {
    super.viewDidLoad()
    NotificationCenter.default.addObserver(self, 
                                           selector: #selector(doThisWhenNotify), 
                                           name: NSNotification.Name(rawValue: myNotificationKey), 
                                           object: nil)
  }