javascript - Noob question: How to get information if google map is loaded (initialized) -

i new google maps api. took sample manual , trying change way need, here trying do: example google maps manual

  var geocoder;   var map;   function initialize() {     geocoder = new google.maps.geocoder();     var latlng = new google.maps.latlng( 40.714353, -74.005973);     var myoptions = {       zoom: 10,       center: latlng,       maptypeid: google.maps.maptypeid.roadmap     }     map = new google.maps.map(document.getelementbyid("map_canvas"), myoptions);   }    function codeaddress() {     var address = document.getelementbyid("address").value;     geocoder.geocode( { 'address': address}, function(results, status) {       if (status == google.maps.geocoderstatus.ok) {         map.setcenter(results[0].geometry.location);         var marker = new google.maps.marker({             map: map,              position: results[0].geometry.location         });       } else {         alert("geocode not successful following reason: " + status);       }     });   } 

i have changed codeaddress function little , trying call on page load this:

function codeaddress(address) {         //var address = document.getelementbyid("address").value;         geocoder.geocode( { 'address': address}, function(results, status) {           if (status == google.maps.geocoderstatus.ok) {             map.setcenter(results[0].geometry.location);             var marker = new google.maps.marker({                 map: map,                  position: results[0].geometry.location             });           } else {             alert("geocode not successful following reason: " + status);           }         });       } codeaddress("some address"); 

but give me javascript error "geocoder undefined". how can make script wait until map loaded , run codeaddress function? don't want path address during initialization.

i hope clear thank in advance.

the problem you're calling codeaddress directly after defining (and hence before initialise() method runs.

consequently need run later on trigger. quick , dirty way set body's onload event; wait until resources (including images) have loaded, might not of problem given map image well.

alternatively, js frameworks give convenient methods fire handlers @ various points in page's lifecycle. if you're using 1 of these, may wish investigate options available , pick best one, depends on number of factors.

critically, don't forget must call initialise() before call codeaddress()!