How to retrieve values submitted via Ajax in PHP?

In PHP, you can use the global variables $_POST or $_GET to retrieve values submitted through Ajax. It depends on whether the Ajax request uses the POST or GET method.

If the data is submitted using the POST method, you can use the $_POST global variable to retrieve the values, for example:

$value = $_POST['key'];

For data submitted using the GET method, you can use the $_GET global variable to retrieve values, for example:

$value = $_GET['key'];

If you are unsure whether the data was submitted using the POST or GET method, you can use the $_REQUEST global variable to retrieve the values. For example:

$value = $_REQUEST['key'];

It is important to note that the global variables $_POST, $_GET, and $_REQUEST are all associative arrays where the keys are the parameter names submitted and the values are the parameter values.