title: How to add multiple Annotations or Pins in MapView in swift
body: <p>I am developing an application which locates the current user location and displays the nearest sport centers to the user's current location. 
  At the moment I am adding the latitude and longitude manually into the <code>viewDidLoad()</code>. </p>
  
  <pre><code>override func viewDidLoad() {
  
      super.viewDidLoad()
      let pinLocation: CLLocationCoordinate2D = CLLocationCoordinate2DMake(43.0757,25.6172)
      let objectAnn = MKPointAnnotation()
      objectAnn.coordinate = pinLocation
      objectAnn.title = "Fitnes"
      objectAnn.subtitle = "Power"
      self.MapView.addAnnotation(objectAnn)
  
      let pinLocation2: CLLocationCoordinate2D = CLLocationCoordinate2DMake(43.0657,25.6272)
      let objectAnn2 = MKPointAnnotation()
      objectAnn2.coordinate = pinLocation2
      objectAnn2.title = "Swimming Pool"
      objectAnn2.subtitle = "Aqua"
      self.MapView.addAnnotation(objectAnn2)
  }
  </code></pre>
  
  <p>Is it possible to save the latitude and longitude coordinates in a JSON file and when the user opens the app, they are uploaded automatically into the function?</p>
  
  <p>Also is it possible out of the coordinations the application to calculate the distance, so that the user is able to set a (km) range and see only these places which are near him?</p>
  
  <p>I would be glad if you provide me with an simple code.</p>