title: How to zoom in/out GoogleMap using button
body: <p>I am trying to Zoom In and Zoom Out a map by using two button on map.
  i am follow this way but not get proper solution-</p>
  
  <p>My code is - </p>
  
  <pre><code>var currentZoom:Float = 10
  </code></pre>
  
  <p>.</p>
  
  <pre><code>func zoomInOut(level:Float)  {
      let camera = GMSCameraPosition.cameraWithLatitude(26.6139, longitude: 77.2090, zoom: level)
  
      self.customMapView.camera = camera
  }
  
  @IBAction func zoomPlus(sender: AnyObject) {
  
      currentZoom = currentZoom + 1;
      print("Plus")
  
      self.customMapView.animateToZoom(currentZoom)
  }
  
  
  @IBAction func zoomMinus(sender: AnyObject) {
  
      currentZoom = currentZoom - 1;
      print("Minus")
  
      self.customMapView.animateToZoom(currentZoom)
  }
  </code></pre>