(PHP 4, PHP 5 < 5.4.0)
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 array.
<?php
// Use of session_register() is deprecated
$barney = "A big purple dinosaur.";
session_register("barney");
// Use of $_SESSION is preferred
$_SESSION["zim"] = "An invader from another planet.";
?>
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.
本函数已自 PHP 5.3.0 起废弃并将自 PHP 5.4.0 起移除。
nameA string holding the name of a variable or an array consisting of variable names or other arrays.
...
成功时返回 TRUE， 或者在失败时返回 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 指令 register_globals 的默认值为 off。PHP 社区鼓励开发者不要依赖于此指令, 用其他手段替代，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, 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 is used, assign values to $_SESSION. For example: $_SESSION['var'] = 'ABC';