Session Functions
PHP Manual

session_unset

Free all session variables

Description

bool session_unset()

The session_unset function frees all session variables currently registered.

Parameters

This function has no parameters.

Return Values

Returns true on success or false on failure.

Changelog

Version Description
7.2.0 The return type of this function is bool now. Formerly, it has been void.

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.

Note:

The use of session_unset is identical to $_SESSION = [].

Caution

This function works only if a session is active. It will not clear the $_SESSION array if the session has not been started yet or has already been destroyed. Use $_SESSION = [] to unset all session variables even if the session is not active.