- var_dump: documentation ( source)
<?php
$foo = 'php5';
$php5['bar']['baz'] = 'Jason';
var_dump($$foo['bar']['baz']);
//php5 = $($foo['bar']['baz']) = $Jason = Young;
echo "\n----------------php7 down------------------\n";
$bar = 'php7';
$php7['bar']['baz'] = 'Young';
var_dump($$bar['bar']['baz']);