- var_dump: documentation ( source)
<?php
$obj = new StdClass();
$obj->foo = 'bar';
$GLOBALS['this'] = $obj;
var_dump($this);
$obj->foo = 'baz';
$foo = 'this';
$$foo = $obj;
var_dump($this);
foo($this);
function foo($this){
$GLOBALS['this']->foo = 'baw';
var_dump($this);
}