(PHP 4, PHP 5)
session_register — Register one or more global variables with the current session
session_register() accepts a variable number of arguments, any of which can be either a string holding the name of a variable or an array consisting of variable names or other arrays. For each name, session_register() registers the global variable with that name in the current session.
You can also create a session variable by simply setting the appropriate member of the $_SESSION or $HTTP_SESSION_VARS (PHP < 4.1.0) array.
<?php
// Use of session_register() is deprecated
$barney = "A big purple dinosaur.";
session_register("barney");
// Use of $_SESSION is preferred, as of PHP 4.1.0
$_SESSION["zim"] = "An invader from another planet.";
// The old way was to use $HTTP_SESSION_VARS
$HTTP_SESSION_VARS["spongebob"] = "He's got square pants.";
?>
If session_start() was not called before this function is called, an implicit call to session_start() with no parameters will be made. $_SESSION does not mimic this behavior and requires session_start() before use.
A string holding the name of a variable or an array consisting of variable names or other arrays.
如果成功则返回 TRUE，失败则返回 FALSE。
If you want your script to work regardless of register_globals, you need to instead use the $_SESSION array as $_SESSION entries are automatically registered. If your script uses session_register(), it will not work in environments where the PHP directive register_globals is disabled.
Note: register_globals 重要说明 自 PHP 4.2.0 起，PHP 中的选项 register_globals 的默认值被设为 off，并且自 PHP 6.0.0 起会被彻底去除。PHP 社区鼓励大家不要依赖于这个选项，用其它方法替代，例如superglobals。
This registers a global variable. If you want to register a session variable from within a function, you need to make sure to make it global using the global keyword or the $GLOBALS[] array, or use the special session arrays as noted below.
If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered(), and session_unregister().
Note: It is currently impossible to register resource variables in a session. For example, you cannot create a connection to a database and store the connection id as a session variable and expect the connection to still be valid the next time the session is restored. PHP functions that return a resource are identified by having a return type of resource in their function definition. A list of functions that return resources are available in the resource types appendix.
If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, assign values to $_SESSION. For example: $_SESSION['var'] = 'ABC';