Google-maps – How to display country borders, US state borders, and city borders using Google Maps

Simply do the following:

I. Declare a global variable:

var markersArray = [];

II. Define a function:

function clearOverlays() {
  for (var i = 0; i < markersArray.length; i++ ) {
    markersArray[i].setMap(null);
  }
  markersArray.length = 0;
}

OR

google.maps.Map.prototype.clearOverlays = function() {
  for (var i = 0; i < markersArray.length; i++ ) {
    markersArray[i].setMap(null);
  }
  markersArray.length = 0;
}

III. Push markers in the 'markerArray' before calling the following:

markersArray.push(marker);
google.maps.event.addListener(marker,"click",function(){});

IV. Call the clearOverlays(); or map.clearOverlays(); function wherever required.

That's it!!

In version 3 of the Maps API you can simply set the scrollwheel option to false within the MapOptions properties:

options = $.extend({
    scrollwheel: false,
    navigationControl: false,
    mapTypeControl: false,
    scaleControl: false,
    draggable: false,
    mapTypeId: google.maps.MapTypeId.ROADMAP
}, options);

If you were using version 2 of the Maps API you would have had to use the disableScrollWheelZoom() API call as follows:

map.disableScrollWheelZoom();

The scrollwheel zooming is enabled by default in version 3 of the Maps API, but in version 2 it is disabled unless explicitly enabled with the enableScrollWheelZoom() API call.