session_name — Getting and Setting PHP Session Name

The session_name() function returns the current session name in PHP. If a $name argument is supplied, it updates the session name to the given value and returns the previous name.

Parameter

name – The session name used in cookies or URLs (e.g., PHPSESSID). It must consist of alphanumeric characters, be short and meaningful; when provided, the current session adopts this name.

Return value

Returns the current session name. If the name parameter is given, the function updates the session name and returns the original name.

Example

<?php
/* Set session name to WebsiteID */
$previous_name = session_name("WebsiteID");
echo "The previous session name was $previous_name<br />";
?>