SUPERGLOBALS(3) 1 SUPERGLOBALS(3) Superglobals - Superglobals are built-in variables that are always available in all scopes Several predefined variables in PHP are "superglobals", which means they are available in all scopes throughout a script. There is no need to do global $variable; to access them within functions or methods. These superglobal variables are: o$GLOBALS o$_SERVER o$_GET o$_POST o$_FILES o$_COOKIE o$_SESSION o$_REQUEST o$_ENV +--------+---------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------+ | 4.1.0 | | | | | | | Superglobals were introduced to PHP. | | | | +--------+---------------------------------------+ Note Variable availability By default, all of the superglobals are available but there are directives that affect this availability. For further information, refer to the documentation for variables_order. Note Dealing with register_globals If the deprecated register_globals directive is set to on then the variables within will also be made available in the global scope of the script. For example, $_POST['foo'] would also exist as $foo. For related information, see the FAQ titled "How does register_globals affect me?" Note Variable variables Superglobals cannot be used as variable variables inside functions or class methods. variable scope, The variables_order directive, The filter extension. PHP Documentation Group SUPERGLOBALS(3)