session_unset

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

session_unset — Destruye todas las variables de una sesión

Descripción

session_unset(): bool

session_unset() destruye todas las variables de la sesión actual.

Parámetros

Esta función no contiene ningún parámetro.

Valores devueltos

Esta función retorna true en caso de éxito o false si ocurre un error.

Historial de cambios

Versión	Descripción
7.2.0	El tipo de retorno de esta función es ahora booleano. Anteriormente, era void.

Notas

Nota:
Si se utiliza $_SESSION utilice unset() para destruir una variable de sesión, es decir unset($_SESSION['nomvariable']);.

Precaución

No se debe destruir $_SESSION con unset($_SESSION) ya que esto desactivará la posibilidad de almacenar variables de sesión a partir del array superglobal $_SESSION.

Nota:
Únicamente session_unset() debe utilizarse para código antiguo que no utiliza $_SESSION.

Precaución
Esta función solo funciona si una sesión está activa. No vaciará el array $_SESSION si la sesión no ha sido iniciada o si ya ha sido destruida. Utilice $_SESSION = [] para eliminar todas las variables de sesión incluso si la sesión no está activa.

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User Contributed Notes 3 notes

down

tim at leethost dot com ¶

13 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);
?>

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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.

down

christian+php at ¶

1 year ago

The solution provided by tim at leethost dot com is nice but you must check a active session first, because else you fill the logs with PHP Errors or Notices depending on your settings. I use it as a function, and it works smooth. 

```php
    /** @return void  */
    public static function sayonara():void
    {
        if (session_status() !== PHP_SESSION_ACTIVE) :void
        {
            session_start();
            session_unset();
            session_destroy();
            session_write_close();
            setcookie(session_name(), '', 0, '/');
            session_regenerate_id(true);
        }        
    }

    sayonara();
```

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