<?php
$a = "abc";
$b = array(1,2,3);
$c = 123;
$vars = get_defined_vars();
unset($_COOKIE);
unset($_POST);
unset($_GET);
unset($_FILES);
unset($GLOBALS);
foreach ($vars as $key => $value) {
var_dump($key);
var_dump($value);
}
//...
var_dump($vars);