I was having troubles with session variables working in some environments and being seriously flaky in others. I was using $_SESSION as an array. It works properly when I used $_SESSION as pointers to arrays. As an example the following code works in some environments and not others.
<?php
//Trouble if I treate $form_convert and $_SESSION['form_convert'] as unrelated items
$form_convert=array();
if (isset($_SESSION['form_convert'])){
$form_convert=$_SESSION['form_convert'];
}
}
?>
The following works well.
<?php
if (isset($_SESSION['form_convert'])){
$form_convert = $_SESSION['form_convert'];
}else{
$form_convert = array();
$_SESSION['form_convert']=$form_convert;
}
?>
$_SESSION
$HTTP_SESSION_VARS [obsolète]
$_SESSION -- $HTTP_SESSION_VARS [obsolète] — Variables de session
Description
Un tableau associatif des valeurs stockées dans les sessions, et accessible au script courant. Elle est automatiquement globale dans tous les contextes d'exécution. Voyez l'extension Sessions pour plus de détails sur comment est utilisée cette variable.
$HTTP_SESSION_VARS contient les mêmes informations, mais n'est pas superglobale. (Notez que $HTTP_SESSION_VARS et $_SESSION sont des variables différentes et que PHP les traite comme telles)
Historique
| Version | Description |
|---|---|
| 4.1.0 | Introduction de $_SESSION, rendant obsolète $HTTP_SESSION_VARS. |
Notes
Note: Ceci est une 'superglobale', ou variable globale automatique. Cela signifie simplement que cette variable est disponible dans tous les contextes du script. Il n'est pas nécessaire de faire global $variable; pour y accéder dans les fonctions ou les méthodes.
$_SESSION
05-Jul-2009 03:47
31-Aug-2008 11:43
Please note that if you have register_globals to On, global variables associated to $_SESSION variables are references, so this may lead to some weird situations.
<?php
session_start();
$_SESSION['test'] = 42;
$test = 43;
echo $_SESSION['test'];
?>
Load the page, OK it displays 42, reload the page... it displays 43.
The solution is to do this after each time you do a session_start() :
<?php
if (ini_get('register_globals'))
{
foreach ($_SESSION as $key=>$value)
{
if (isset($GLOBALS[$key]))
unset($GLOBALS[$key]);
}
}
?>
17-Aug-2008 03:28
Unlike a real PHP array, $_SESSION keys at the root level must be valid variable names.
<?php
$_SESSION[1][1] = 'cake'; // fails
$_SESSION['v1'][1] = 'cake'; // works
?>
I imagine this is an internal limitation having to do with the legacy function session_register(), where the registered global var must similarly have a valid name.
02-Aug-2008 01:16
You may have trouble if you use '|' in the key:
$_SESSION["foo|bar"] = "fuzzy";
This does not work for me. I think it's because the serialisation of session object is using this char so the server reset your session when it cannot read it.
To make it work I replaced '|' by '_'.
