Query Strings in AJAX

When you make a request using AJAX you are simply making a request to a server URL. The URL is typically an application that is developed to provide some kind of response. What determines the key/values that a URL receives is determined by the application, which is ultimately determined by a developer.

If I wanted to make a web form that when I type in a zipcode it will return a US City and State, I could create a PHP script to do this. I know that I want to pass in a zipcode to get a city/state, so I will use zipcode as my parameter. The URL may look something like this:

http://www.myapp.com/myAJAXScript.php?zipcode=94101

The above script will return a JSON file that would contain my city and state information. The URL would be what I would call within my Javascript AJAX call.

So to wrap it up - it is the URL endpoint that determines what key/values you pass in.

OK thanks.