- var_dump: documentation ( source)
<?php
$it1 = new ArrayIterator(array(1,2,3));
$it2 = new ArrayIterator(array(4,5,6));
$multipleIterator = new MultipleIterator();
$multipleIterator->attachIterator($it1);
$multipleIterator->attachIterator($it2, 'second');
foreach ($multipleIterator as $key => $value) {
var_dump($key, $value);
}