Session Functions
PHP Manual

session_unset

Free all session variables

Description

void session_unset ( void )

The session_unset function frees all session variables currently registered.

Return Values

No value is returned.

Notes

Note:

If $_SESSION is used, use unset to unregister a session variable, i.e. unset ($_SESSION['varname']);.

Caution

Do NOT unset the whole $_SESSION with unset($_SESSION) as this will disable the registering of session variables through the $_SESSION superglobal.