Question

I’ve got this piece of code where I’m trying to position a set of markers in a google map:

  for(var i = 0; i < postcodes.length; i++) {
    var address = postcodes[i].innerHTML +", uk";
    geocoder.geocode({'address': address}, function(results, status){
      if (status == google.maps.GeocoderStatus.OK) {
        var marker = new google.maps.Marker({
          position: results[i].geometry.location,
          map: map,
          icon: image,
        });
      } else {
        alert("Geocode was not successful for the following reason: " + status);
      }
   });
 }

However, this returns as undefined where I try to set the position. If I use a number (0) instead of the variable i in results[#] it works fine but I can’t iterate through the results then. Has anyone come across this problem before?

Thanks,

Answer 1

The problem is that start one for loop that iterates through the postal codes:

for(var i = 0; i < postcodes.length; i++) {

So i is an index in the array of postcodes. Then you try to use that index in the object of results return from your geocoding request for postcodes[i]; but the two arrays are unrelated. Variable results is the results for postcodes[i], and contains all the search results for that postcode. Therefore, results[0] is the closest result to one postcode.

I think what you want is:

for(var i = 0, num = postcodes.length; i < num; i++) { // loop through postal codes
  geocoder.geocode(
    {
      address: postcodes[i].innerHTML + ", uk"
    },
    function(results, status) {
      if (status != google.maps.GeocoderStatus.OK) {
        alert("Geocode was not successful for the following reason: " + status);
        return false;
      }
      for (var i = 0, num = results.length; i < num; i++) { // loop through results
        var marker = new google.maps.Marker({
          position: results[i].geometry.location,
          map: map,
          icon: image
        });
      }
    }
  ); // end geocode request
}

If you only want to show the closest results, omit the second for loop and use results[0] instead of results[i].