Marker Labels

This example creates a map where each click by the user creates a marker that's labeled with a single alphabetical character.

Read the documentation.

// In the following example, markers appear when the user clicks on the map.
// Each marker is labeled with a single alphabetical character.
var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var labelIndex = 0;

function initialize() {
  var bangalore = { lat: 12.97, lng: 77.59 };
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 12,
    center: bangalore
  });

  // This event listener calls addMarker() when the map is clicked.
  google.maps.event.addListener(map, 'click', function(event) {
    addMarker(event.latLng, map);
  });

  // Add a marker at the center of the map.
  addMarker(bangalore, map);
}

// Adds a marker to the map.
function addMarker(location, map) {
  // Add the marker at the clicked location, and add the next-available label
  // from the array of alphabetical characters.
  var marker = new google.maps.Marker({
    position: location,
    label: labels[labelIndex++ % labels.length],
    map: map
  });
}

google.maps.event.addDomListener(window, 'load', initialize);
<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 src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></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>Marker Labels</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>
    <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY"></script>
    <script>
      // In the following example, markers appear when the user clicks on the map.
      // Each marker is labeled with a single alphabetical character.
      var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
      var labelIndex = 0;

      function initialize() {
        var bangalore = { lat: 12.97, lng: 77.59 };
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 12,
          center: bangalore
        });

        // This event listener calls addMarker() when the map is clicked.
        google.maps.event.addListener(map, 'click', function(event) {
          addMarker(event.latLng, map);
        });

        // Add a marker at the center of the map.
        addMarker(bangalore, map);
      }

      // Adds a marker to the map.
      function addMarker(location, map) {
        // Add the marker at the clicked location, and add the next-available label
        // from the array of alphabetical characters.
        var marker = new google.maps.Marker({
          position: location,
          label: labels[labelIndex++ % labels.length],
          map: map
        });
      }

      google.maps.event.addDomListener(window, 'load', initialize);
    </script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>