php man page for session_is_registered

SESSION_IS_REGISTERED(3)						 1						  SESSION_IS_REGISTERED(3)

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

SYNOPSIS
       bool session_is_registered (string  $name)

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

       Warning

	      This function has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.

PARAMETERS
	      o $name
		- The variable name.

RETURN VALUES
       session_is_registered(3) 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(3) to check a variable is registered in $_SESSION.

       Caution

	       If  you	are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(3), session_is_registered(3) and session_unregis-
	      ter(3).

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