(PHP 4 >= 4.0.4, PHP 5)
This function returns an multidimensional array containing a list of all defined variables, be them environment, server or user-defined variables.
<?php$b = array(1, 1, 2, 3, 5, 8);$arr = get_defined_vars();// print $bprint_r($arr["b"]);/* print path to the PHP interpreter (if used as a CGI) * e.g. /usr/local/bin/php */echo $arr["_"];// print the command-line parameters if anyprint_r($arr["argv"]);// print all the server varsprint_r($arr["_SERVER"]);// print all the available keys for the arrays of variablesprint_r(array_keys(get_defined_vars()));?>
See also isset(), get_defined_functions() and get_defined_constants().