How to create Ajax based PHP application

What is Ajax?

AJAX full form is Asynchronous JavaScript & XML. It is a technology that reduces the interactions between the server and client. It does this by updating only part of a web page rather than the whole page.The asynchronous interactions are initiated by JavaScript.The purpose of AJAX is to exchange small amounts of data with server without page refresh.

JavaScript is a client side scripting language. It is executed on the client side by the web browsers that support JavaScript.JavaScript code only works in browsers that have JavaScript enabled.

XML is the acronym for Extensible Markup Language. It is used to encode messages in both human and machine readable formats. It’s like HTML but allows you to create your custom tags. For more details on XML, see the article on XML

Why use AJAX?

  • It allows developing rich interactive web applications just like desktop applications.
  • Validation can be performed done as the user fills in a form without submitting it. This can be achieved using auto completion. The words that the user types in are submitted to the server for processing. The server responds with keywords that match what the user entered.
  • It can be used to populate a dropdown box depending on the value of another dropdown box
  • Data can be retrieved from the server and only a certain part of a page updated without loading the whole page. This is very useful for web page parts that load things like
    • Tweets
    • Commens
    • Users visiting the site etc.

$frameworks = array("CodeIgniter","Zend Framework","Cake PHP","Kohana") ;

$name = $_GET["name"];

if (strlen($name) > 0) {

    $match = "";

    for ($i = 0; $i < count($frameworks); $i++) {

        if (strtolower($name) == strtolower(substr($frameworks[$i], 0, strlen($name)))) {

            if ($match == "") {

                $match = $frameworks[$i];

            } else {

                $match = $match . " , " . $frameworks[$i];





echo ($match == "") ? 'no match found' : $match;


Step 3) Creating the JS script


How to create PHP Ajax  based Application

The above example demonstrates the concept of AJAX and how it can help us create rich interaction applications.


  • AJAX is the acronym for Asynchronous JavaScript and XML
  • AJAX is a technology used to create rich interaction applications that reduce the interactions between the client and the server by updating only parts of the web page.
  • Internet Explorer version 5 and 6 use ActiveXObject to implement AJAX operations.
  • Internet explorer version 7 and above and browsers Chrome, Firefox, Opera, and Safari use XMLHttpRequest.