wesbos wesbos - 5 months ago 50
Javascript Question

Google Maps JS API v3 - Simple Multiple Marker Example

Fairly new to the Google Maps Api. I've got an array of data that I want to cycle through and plot on a map. Seems fairly simple, but all the multi-marker tutorials I have found are quite complex.

Lets use the data array from google's site for an example:

var locations = [
['Bondi Beach', -33.890542, 151.274856, 4],
['Coogee Beach', -33.923036, 151.259052, 5],
['Cronulla Beach', -34.028249, 151.157507, 3],
['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
['Maroubra Beach', -33.950198, 151.259302, 1]
];


I simply want to plot all of these points and have an infoWindow pop up when clicked to display the name.

Any help is greatly appreciated!

Answer

This is the simplest I could reduce it to:

<!DOCTYPE html>
<html> 
<head> 
  <meta http-equiv="content-type" content="text/html; charset=UTF-8" /> 
  <title>Google Maps Multiple Markers</title> 
  <script src="http://maps.google.com/maps/api/js?sensor=false" 
          type="text/javascript"></script>
</head> 
<body>
  <div id="map" style="width: 500px; height: 400px;"></div>

  <script type="text/javascript">
    var locations = [
      ['Bondi Beach', -33.890542, 151.274856, 4],
      ['Coogee Beach', -33.923036, 151.259052, 5],
      ['Cronulla Beach', -34.028249, 151.157507, 3],
      ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
      ['Maroubra Beach', -33.950198, 151.259302, 1]
    ];

    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 10,
      center: new google.maps.LatLng(-33.92, 151.25),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });

    var infowindow = new google.maps.InfoWindow();

    var marker, i;

    for (i = 0; i < locations.length; i++) {  
      marker = new google.maps.Marker({
        position: new google.maps.LatLng(locations[i][1], locations[i][2]),
        map: map
      });

      google.maps.event.addListener(marker, 'click', (function(marker, i) {
        return function() {
          infowindow.setContent(locations[i][0]);
          infowindow.open(map, marker);
        }
      })(marker, i));
    }
  </script>
</body>
</html>

Screenshot:

Google Maps Multiple Markers

There is some closure magic happening when passing the callback argument to the addListener method. This can be quite a tricky topic, if you are not familiar with how closures work. I would suggest checking out the following Mozilla article for a brief introduction, if it is the case: