Toggle Google Maps markers

I taken some code form another post to start me off but trying to get it to do what I need. I need to set up functions to show/hide markers when they are checked and also to assign appropriate icons to the marker categories ie, Walk, Fish.

To start I need to get the show hide functions to work which currently aren't.

You can find a demo here...http://jsfiddle.net/huMtu/

The problem you have is that the locations variable is an array of information - its not actually the marker on the Google Map - that means that you cannot call the method setVisible() on it....

What you need to do is store each of the markers in a separate array then call the setVisible method against the element of this new array .... I have updated the JSFiddle -> http://jsfiddle.net/huMtu/1/

here is the JS part :

var markers = new Array(); // Used to store the google markers
    var locations = [
      ['Bondi Beach', 'Some text goes here<br />text', 'Walk', -33.890542, 151.274856, 4],
      ['Coogee Beach', 'Some text goes here<br />text', 'Fish', -33.923036, 151.259052, 5],
      ['Cronulla Beach', 'Some text goes here<br />text', 'Fish', -34.028249, 151.157507, 3],
      ['Manly Beach', 'Some text goes here<br />text', 'Walk', -33.80010128657071, 151.28747820854187, 2],
      ['Maroubra Beach', 'Some text goes here<br />text', 'Walk', -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][3], locations[i][4]),
        map: map
      });

        markers.push(marker); // Add the current marker to the array for later processing

      google.maps.event.addListener(marker, 'click', (function(marker, i) {
        return function() {
          infowindow.setContent(locations[i][0]+"<br />"+locations[i][2]+"<br />"+locations[i][1]);
          infowindow.open(map, marker);
        }
      })(marker, i));
    }

    // == shows all markers of a particular category, and ensures the checkbox is checked ==
      function show(category) {
        for (var i=0; i<locations.length; i++) {
          if (locations[i][2] == category) {
            markers[i].setVisible(true); // call the setVisible method of the marker
          }
        }
      }

      // == hides all markers of a particular category, and ensures the checkbox is cleared ==
      function hide(category) {
        for (var i=0; i<locations.length; i++) {
          if (locations[i][2] == category) {
            markers[i].setVisible(false); // call the setVisible method of the marker
          }
        }
      }

      // == show or hide the categories initially ==
        show("Walk");
        hide("Fish");

working fiddle (with publicly available icons)