asp.net - Fetch Latitude Longitude by passing postcodes to maps.google.com using Javascript

Question

I have Postcode in my large database, which contains values like SL5 9JH, LU1 3TQ etc.

Now when I am pasting above postcode to maps.google.com it's pointing to a perfect location..

My requirement is like I want to pass post codes to maps.google.com and it should return a related latitude and longitude of that pointed location, that I want to store in my database.

So, most probably there should be some javascript for that... If anybody have another idea regarding that please provide it..

Thanks in advance...

Answer 1

A quick note for those finding this SO answer. The answer by Daniel Vassallo uses the Google Geocoding API V2 which has now been deprecated. The new v3 API uses a request format like this:

http://maps.googleapis.com/maps/api/geocode/output?parameters

An example for a postcode lookup, returning the data in JSON format is:

http://maps.googleapis.com/maps/api/geocode/json?address=SL59JH,+UK&sensor=false

This returns a JSON array that includes the lat and long in results->geometry->location->lat and results->geometry->location->lng

Example response:

{
 "results" : [
  {
     "address_components" : [
        {
           "long_name" : "SL5 9JH",
           "short_name" : "SL5 9JH",
           "types" : [ "postal_code" ]
        },
        {
           "long_name" : "Windsor and Maidenhead",
           "short_name" : "Windsor and Maidenhead",
           "types" : [ "administrative_area_level_2", "political" ]
        },
        {
           "long_name" : "United Kingdom",
           "short_name" : "GB",
           "types" : [ "country", "political" ]
        },
        {
           "long_name" : "Ascot",
           "short_name" : "Ascot",
           "types" : [ "postal_town" ]
        }
     ],
     "formatted_address" : "Ascot, Windsor and Maidenhead SL5 9JH, UK",
     "geometry" : {
        "bounds" : {
           "northeast" : {
              "lat" : 51.39655490000001,
              "lng" : -0.66024660
           },
           "southwest" : {
              "lat" : 51.39457330,
              "lng" : -0.6624574999999999
           }
        },
        "location" : {
           "lat" : 51.39539040,
           "lng" : -0.66096740
        },
        "location_type" : "APPROXIMATE",
        "viewport" : {
           "northeast" : {
              "lat" : 51.39691308029150,
              "lng" : -0.6600030697084980
           },
           "southwest" : {
              "lat" : 51.39421511970851,
              "lng" : -0.6627010302915021
           }
        }
     },
     "types" : [ "postal_code" ]
  }
],
"status" : "OK"
}

The API spec is available here: https://developers.google.com/maps/documentation/geocoding/