I have a marker called chicagoMarker and each time the user zooms in closer I would like to alert them if they are getting closer to chicago. I am not sure if I have a problem with my event listener in this instance.

if (score==0) {
        zoom = map.getZoom();
        if (bounds.contains(chicagoMarker)){
            window.alert("Good Job!");

  • try troubleshooting by moving the window.alert() before .setmap(), or even before (score==0)... does this produce an alert?
    – kttii
    Commented Nov 11, 2016 at 14:14

1 Answer 1


Not sure about your code... You create a variable zoom, but then don't use it. You refer to a variable bounds, but I don't see that being created anywhere. You have an event listener set up on the Marker for 'bounds_changed', but the Marker class hasn't got that as an event you can listen for. See the list of events available under 'Events' here: https://developers.google.com/maps/documentation/javascript/reference#Marker

Instead set the event listener on the Map object, for the same event. And I've changed it to see if the Marker's position is inside the Bounds:

if (score == 0) {

    map.addListener('bounds_changed', function() {
        var bounds = map.getBounds();
        if (bounds.contains(chicagoMarker.getPosition())) {
            window.alert("Good Job!");

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