$it = new RecursiveArrayIterator(array(1, 2, array(3, 4, array(5, 6, 7), 8), 9, 10));
$tit = new RecursiveTreeIterator($it);
foreach( $tit as $key => $value ){
echo $value . PHP_EOL;
}
/* Will output
|-1
|-2
|-Array
| |-3
| |-4
| |-Array
| | |-5
| | |-6
| | \-7
| \-8
|-9
\-10
*/