How to decode addresses into coordinates and vice versa

Webapps in geographical context, often comprise the problem that postal addresses have to be converted into coordinates, in order to use them for navigational purposes. Also the other way round is sometimes required, like finding an appropriate address on the base of a given set of coordinates. Implementing an own coordinates to address converter is usually impossible for Webapp Designers or Programmer's, as it means to maintain a huge amount of data, as well as sophisticated algorithms to access the geographic data.
1 answer

Using Google's Geocoding Webservice API

Google offers a comfortable way, to convert coordinates into addresses (if applicable) as well as converting addresses into coordinates. The basic way to do so is to create an inquiry on the Google Maps API. It looks like this:

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

whereas the phrase "output" is a placeholder for a json handover or a XML handover of parameters. The parameters divide on the first side into a location, which can be given in form of an address, coordinates (latitude and longiude) or in form of a "component". And on the other hand they divide into a flag, which determines whether the inquiry was sent by a device with location detecting capabilites or not. Besides to these basic parameters there are also several optional parameters like language, bounds or region.

A Geocoding enquiry via Json looks like this:
http://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheat...

and like XML it looks like this:
http://maps.googleapis.com/maps/api/geocode/xml?address=1600+Amphitheatr...

Depending on the given format the enquiry is processed respectively, and the result is returned in form of a Json array and a status flag. The result has to be extracted from the array, in case the status flag returns that the enquiry delivered an appropriate result.