Recursive Iteration of a Multidimensional Array Using SPL Iterators

recursive_array_iterator.php

<?php

$nav_menu = array("Level 1" => array("Level 1 child (a)", "Level 1 child (b)"),
                  "Level 2" => array("Level 2 child (a)" => 
                                      array("Level 2.1 child (a)" => 
                                               array("Level 2.2 child (a)"), 
                                            "Level 2.1 Child (b)"
                                      ), 
                                     "Level 2 child (b)"
                                    ),
                  "Level 3" 
             );

//print_r($nav_menu);

$rai = new RecursiveArrayIterator($nav_menu);

$rii = new RecursiveIteratorIterator($rai, RecursiveIteratorIterator::SELF_FIRST);

$str ="<ul>";

foreach($rii as $key => $value ) {

    echo "<b>Depth: </b>" . $rii->getDepth() ."<br>";
    echo "<b>Key: </b>" . $key . "<br>";
    echo "<b>Value: </b>"; print_r($value); echo "<br>";
    echo "*************************<br>";

     if($rii->callHasChildren()){
         $str .= "<li>" . $rii -> key();
         $str .= "<ul>";
         //Find out how many children the current parent has
         $children = $rii->callGetChildren();
         $childrenCount = $children->count();
     }
     else {

       $str.= "<li>" . $rii -> current() . "</li>";
       //Close the unordered list if the current child is the final child
       if($rii -> key() == $childrenCount-1) $str.= "</ul>";
       
    }
    

 }

echo($str);


?>