PHP (PHP Hypertext Preprocessor): PHP

AJAX is used to create more interactive applications.

When a user types a character in the input field above, the function "showHint()" is executed. The function is triggered by the "onkeyup" event:

Start typing a name in the input field below:

First name: 

Suggestions:

Source code explanation:

If the input field is empty (str.length==0), the function clears the content of the txtHint placeholder and exits the function.

If the input field is not empty, the showHint() function executes the following:

Create an XMLHttpRequest object
Create the function to be executed when the server response is ready
Send the request off to a file on the server
Notice that a parameter (q) is added to the URL (with the content of the input field)

The PHP File

The page on the server called by the JavaScript above is a PHP file called "gethint.php".

The source code in "gethint.php" checks an array of names, and returns the corresponding name(s) to the browser:

0

if (strlen($q) > 0)

  {

  $hint="";

  for($i=0; $i

Explanation: If there is any text sent from the JavaScript (strlen($q) > 0), the following happens:

Find a name matching the characters sent from the JavaScript
If no match were found, set the response string to "no suggestion"
If one or more matching names were found, set the response string to all these names
The response is sent to the "txtHint" placeholder