I was having a problem clearing all session variables, deleting the session, and creating a new session without leaving old session stuff behind in all browsers. The below code is perfect for a logout script to totally delete everything and start new. It even works in Chrome which seems to not work as other browsers when trying do logout and start a new session.
<?php
session_start();
session_unset();
session_destroy();
session_write_close();
setcookie(session_name(),'',0,'/');
session_regenerate_id(true);
?>
session_unset
(PHP 4, PHP 5, PHP 7, PHP 8)
session_unset — Löscht alle Session-Variablen
Beschreibung
session_unset(): bool
Die Funktion session_unset() löscht alle Session-Variablen, die gegenwärtig registriert sind.
Parameter-Liste
Diese Funktion besitzt keine Parameter.
Rückgabewerte
Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.
Changelog
| Version | Beschreibung |
|---|---|
| 7.2.0 | Der Rückgabetyp dieser Funktion ist nun bool. Zuvor war es void. |
Anmerkungen
Hinweis:
Wenn $_SESSION verwendet wird, kann eine Session-Variable mit unset() gelöscht werden, d. h.
unset($_SESSION['varname']);.
Achtung
$_SESSION darf NICHT komplett mit
unset($_SESSION) gelöscht werden, weil dies die Registrierung
von Session-Variablen über die Superglobale $_SESSION
deaktivieren würde.
Hinweis:
Die Funktion session_unset() entspricht
$_SESSION = [].
Achtung
Diese Funktion funktioniert nur, wenn es eine aktive Session gibt. Wenn
die Sitzung noch nicht gestartet wurde oder bereits zerstört wurde, wird
das Array $_SESSION nicht gelöscht. Um alle Variablen
der Session zu löschen, auch wenn die Session nicht aktiv ist, kann
$_SESSION = [] verwendet werden.
add a note
User Contributed Notes 4 notes
tim at leethost dot com ¶
12 years ago
jerry ¶
9 years ago
The difference between both session_unset and session_destroy is as follows:
session_unset just clears out the session for usage. The session is still on the users computer. Note that by using session_unset, the variable still exists. session_unset just remove all session variables. it does not destroy the session....so the session would still be active.
Using session_unset in tandem with session_destroy however, is a much more effective means of actually clearing out data. As stated in the example above, this works very well, cross browser. session_destroy is destroy the session. session_destroy() to kill all session information.....This is the more secure function to use.
Jeroen ¶
19 years ago
note to Jason: I don't know the exact mechanics of it (since I'm quite new to sessions) but I think you need to use session_unset() BEFORE you can use session_destroy() at all. I thought that session_unset() was for scripted variables, and session_destroy() just for anything saved on your side regarding the session.
zach at zkwarta dot com ¶
19 years ago
The difference between both session_unset and session_destroy is as follows:
session_unset just clears out the sesison for usage. The session is still on the users computer. Note that by using session_unset, the variable still exists.
Using session_unset in tandem with session_destroy however, is a much more effective means of actually clearing out data. As stated in the example above, this works very well, cross browser:
session_unset();
session_destroy();
I noticed that in firefox, one could simply use sesison_unset and the session would be cleared. When trying this on IE, I was horrified to find out that the data was still there, so I had to use session destroy.
