Complex Polylines

Click two or more points on the map to draw polylines.

// This example creates an interactive map which constructs a polyline based on
// user clicks. Note that the polyline only appears once its path property
// contains two LatLng coordinates.

var poly;
var map;

function initMap() {
  map = new google.maps.Map(document.getElementById('map'), {
    zoom: 7,
    center: {lat: 41.879, lng: -87.624}  // Center the map on Chicago, USA.
  });

  poly = new google.maps.Polyline({
    strokeColor: '#000000',
    strokeOpacity: 1.0,
    strokeWeight: 3
  });
  poly.setMap(map);

  // Add a listener for the click event
  map.addListener('click', addLatLng);
}

// Handles click events on a map, and adds a new point to the Polyline.
function addLatLng(event) {
  var path = poly.getPath();

  // Because path is an MVCArray, we can simply append a new coordinate
  // and it will automatically appear.
  path.push(event.latLng);

  // Add a new marker at the new plotted point on the polyline.
  var marker = new google.maps.Marker({
    position: event.latLng,
    title: '#' + path.getLength(),
    map: map
  });
}

<div id="map"></div>

/* Always set the map height explicitly to define the size of the div
 * element that contains the map. */
#map {
  height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

<!-- Replace the value of the key parameter with your own API key. -->
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>

Try it yourself

You can experiment with this code in JSFiddle by clicking the <> icon in the top-right corner of the code window.

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Complex Polylines</title>
    <style>
      /* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
      #map {
        height: 100%;
      }
      /* Optional: Makes the sample page fill the window. */
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <script>

      // This example creates an interactive map which constructs a polyline based on
      // user clicks. Note that the polyline only appears once its path property
      // contains two LatLng coordinates.

      var poly;
      var map;

      function initMap() {
        map = new google.maps.Map(document.getElementById('map'), {
          zoom: 7,
          center: {lat: 41.879, lng: -87.624}  // Center the map on Chicago, USA.
        });

        poly = new google.maps.Polyline({
          strokeColor: '#000000',
          strokeOpacity: 1.0,
          strokeWeight: 3
        });
        poly.setMap(map);

        // Add a listener for the click event
        map.addListener('click', addLatLng);
      }

      // Handles click events on a map, and adds a new point to the Polyline.
      function addLatLng(event) {
        var path = poly.getPath();

        // Because path is an MVCArray, we can simply append a new coordinate
        // and it will automatically appear.
        path.push(event.latLng);

        // Add a new marker at the new plotted point on the polyline.
        var marker = new google.maps.Marker({
          position: event.latLng,
          title: '#' + path.getLength(),
          map: map
        });
      }
    </script>
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
    </script>
  </body>
</html>