Google Maps API v3: How to remove all markers?

Question

In Google Maps API v2, if I wanted to remove all the map markers, I could simply do:

map.clearOverlays();

How do I do this in Google Maps API v3?

Looking at the Reference API, it's unclear to me.

Answer 1

It seems that there is no such function in V3 yet.

People suggest to keep references to all markers you have on the map in an array. And then when you want to delete em all, just loop trough the array and call .setMap(null) method on each of the references.

See this question for more info/code.

My version:

google.maps.Map.prototype.markers = new Array();

google.maps.Map.prototype.getMarkers = function() {
    return this.markers
};

google.maps.Map.prototype.clearMarkers = function() {
    for(var i=0; i<this.markers.length; i++){
        this.markers[i].setMap(null);
    }
    this.markers = new Array();
};

google.maps.Marker.prototype._setMap = google.maps.Marker.prototype.setMap;

google.maps.Marker.prototype.setMap = function(map) {
    if (map) {
        map.markers[map.markers.length] = this;
    }
    this._setMap(map);
}

The code is edited version of this code http://www.lootogo.com/googlemapsapi3/markerPlugin.html I removed the need to call addMarker manually.

Pros

• Doing this way you keep the code compact and in one place (doesn't pollute the namespace).
• You don't have to keep track of the markers yourself anymore you can always find all the markers on the map by calling map.getMarkers()

Cons

• Using prototypes and wrappers like I did now makes my code dependent on Google code, if they make a mayor change in their source this will break.
• If you don't understand it then you won't be able to fix it if does break. The chances are low that they're going to change anything which will break this, but still..
• If you remove one marker manually, it's reference will still be in markers array. (You could edit my setMap method to fix it, but at the cost of looping trough markers array and removing the reference)

Answer 2

google.maps.Map.prototype.markers = new Array();

google.maps.Map.prototype.addMarker = function(marker) {
    this.markers[this.markers.length] = marker;
};

google.maps.Map.prototype.getMarkers = function() {
    return this.markers
};

google.maps.Map.prototype.clearMarkers = function() {
    for(var i=0; i<this.markers.length; i++){
        this.markers[i].setMap(null);
    }
    this.markers = new Array();
};

I don't think there is one in V3 so I used the above custom implementation.

Disclaimer: I did not write this code but I forgot to retain a reference when I merged it into my codebase so I don't know where it came from.

Answer 3

The "set_map" function posted in both answers appears to no longer work in Google Maps v3 API.

I wonder what happened

Update:

It appears Google changed their API such that "set_map" is not "setMap".

http://code.google.com/apis/maps/documentation/v3/reference.html

Answer 4

Same problem. This code doesn't work anymore.

I've corrected it, change clearMarkers method this way:

set_map(null) ---> setMap(null)

google.maps.Map.prototype.clearMarkers = function() {
    for(var i=0; i < this.markers.length; i++){
        this.markers[i].setMap(null);
    }
    this.markers = new Array();
};

Answer 5

Simply do the following:

I. Declare a global variable:

var markersArray = [];

II. Define a function:

function clearOverlays() {
  if (markersArray) {
    for (i in markersArray) {
      markersArray[i].setMap(null);
    }
  }
}

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

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

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

That's it!!

Hope that will help you.