PHP Velho Oeste 2024

session_unset

(PHP 4, PHP 5, PHP 7, PHP 8)

session_unsetУдалить все переменные сессии

Описание

session_unset(): bool

Функция session_unset() удаляет все зарегистрированные переменные текущей сессии.

Список параметров

У этой функции нет параметров.

Возвращаемые значения

Возвращает true в случае успешного выполнения или false в случае возникновения ошибки.

Список изменений

Версия Описание
7.2.0 Теперь возвращаемый тип этой функции bool. Раньше был тип void.

Примечания

Замечание:

При использовании $_SESSION для удаления переменных сессии, то используйте функцию unset(). Например, unset($_SESSION['varname']);.

Предостережение

НЕ удаляйте весь массив $_SESSION с помощью unset($_SESSION), так как это приведёт к невозможности регистрации новых переменных через суперглобальный массив $_SESSION

Замечание:

Использование функции session_unset() идентично $_SESSION = [].

Предостережение

Функция работает только в том случае, если сессия активна. Она не очистит массив $_SESSION, если сессия ещё не запущена или уже уничтожена. Используйте $_SESSION = [] для удаления всех переменных сессии, даже если сессия не активна.

add a note

User Contributed Notes 4 notes

up
39
tim at leethost dot com
12 years ago
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);
?>
up
21
jerry
8 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.
up
-15
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.
up
-22
zach at zkwarta dot com
18 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.
To Top