title: UiAlertView or UiAlertController to display only once in Swift
body: <p>How can I get my <code>UiAlertController</code> or <code>UIAlertView</code> to display only once in Swift?</p>
  
  <pre><code>override func viewDidLoad() {
  
      var defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
  
      if let nameIsNotNill = defaults.objectForKey("name") as? String {
          self.name.text = defaults.objectForKey("name") as String
      }
  
      if let phoneIsNotNill = defaults.objectForKey("phone") as? String {
          self.phone.text = defaults.objectForKey("phone") as String
      }
  
      var alert = UIAlertController(title: "Disclaimer", message: "WE STRIVES TO PROVIDE ACCURATE, UP-TO-DATE INFORMATION ON THIS APPS.", preferredStyle: UIAlertControllerStyle.Alert)
  
      alert.addAction(UIAlertAction(title: "Agree", style: UIAlertActionStyle.Default, handler: nil))
      alert.addAction(UIAlertAction(title: "Disagree", style: UIAlertActionStyle.Default, handler: nil))
  
      self.presentViewController(alert, animated: true, completion: nil)
  
      super.viewDidLoad()
  
  }
  </code></pre>