<?php
$array = array(
    array(
        array(
            array(
                'leaf-0-0-0-0',
                'leaf-0-0-0-1'
            ),
            'leaf-0-0-0'
        ),
        array(
            array(
                'leaf-0-1-0-0',
                'leaf-0-1-0-1'
            ),
            'leaf-0-1-0'
        ),
        'leaf-0-0'
    )
);
$iterator = new RecursiveIteratorIterator(
    new RecursiveArrayIterator($array),
    $mode
);
foreach ($iterator as $key => $leaf) {
    echo "$key => $leaf", PHP_EOL;
}
?>
     
    
     Affichage avec $mode = RecursiveIteratorIterator::LEAVES_ONLY
    
0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
0 => leaf-0-0-0
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
0 => leaf-0-1-0
0 => leaf-0-0
 
    
     Affichage avec $mode = RecursiveIteratorIterator::SELF_FIRST
    
0 => Array
0 => Array
0 => Array
0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
1 => leaf-0-0-0
1 => Array
0 => Array
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
1 => leaf-0-1-0
2 => leaf-0-0
 
    
     Affichage avec $mode = RecursiveIteratorIterator::CHILD_FIRST
    
0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
0 => Array
1 => leaf-0-0-0
0 => Array
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
0 => Array
1 => leaf-0-1-0
1 => Array
2 => leaf-0-0
0 => Array