Sessions
PHP Manual

session_is_registered

(PHP 4, PHP 5)

session_is_registered — Find out whether a global variable is registered in a session

Description

bool session_is_registered ( string $name )

Finds out whether a global variable is registered in a session.

Parameters

name

The variable name.

Return Values

session_is_registered() returns TRUE if there is a global variable with the name name registered in the current session, FALSE otherwise.

Notes

Note: If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, use isset() to check a variable is registered in $_SESSION.

Caution

If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered() and session_unregister().


Sessions
PHP Manual