Get Longitude and Latitude using JavaScript and set these to vars

Question

Today is my first day using the Google Maps API. Now I have a DIV with an id of "map" the following code...

function initializeMap() {

        var opts = {
            center: new google.maps.LatLng( 0, 0), // ignore the zero values for now
            zoom: 10,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        map = new google.maps.Map(document.getElementById('map'), opts);
        geocoder = new google.maps.Geocoder();
}

and I call this using window.onload = initializeMap

Okay I'd like to center the map in my current location. I know I can get the long and lat using

navigator.geolocation.getCurrentPosition(displayLocation);

function displayLocation(position) {
    var latitude = position.coords.latitude;
    var longitude = position.coords.longitude; 
 }

Now I'm a little lost with how the position object is pushed back to success handler displayLocation. Anyway how can I pass the latitude & longitude to the initializeMap() function like so...

center: new google.maps.LatLng( latitude, longitude)

I'm currently looking at the Google Maps API docs as I'm sure there's a method to get this but I'd like to use the latitude, longitude in different functions so I guess I'm asking how can I make these variables accessible to all functions (like a global but not a bad global) instead of being only available to the displayLocation function . Sorry if this is worded poorly... if I'm confusing people please say and I'll reword this question.

Fabrizio Calderan Fabrizio Calderan · Accepted Answer · 2012-05-25T12:31:30

just declare

var latitude, longitude;

into a parent scope, so the function is

function displayLocation(position) {
    latitude = position.coords.latitude; /* no var keyword */
    longitude = position.coords.longitude; 
}

of course the choice of the scope in which you should define those variables is up to you. Also, be aware that they will be undefined until displayLocation is not called

Get Longitude and Latitude using JavaScript and set these to vars

1 Answers