Question

I have this function whose essential operations are outlined as follows:

function render($index) {     foreach($things[$index] as $key => $data) {         echo '<div>';         /* irrelevant operations */         if(isset($data['id'])) {             echo '<div class='wrap'>';             render($things[$data['id']]);             echo '</div>';         }         echo '</div>';     } } 

I can not for the life of me figure out how to optimize this function; I fear that PHP implode if the call stack gets too big.

Is there any way to optimize this function?

Answer 1

This code is untested, but from the top of my head, the iterative function should look something like this:

function render($index){     $stack = array();     array_push($index);      $pre = '';     $post = '';      while(!empty($stack)){         $idx = array_pop($stack);          foreach($things[$idx] as $key => $value){             $pre .= '<1>';             $spost = '';              if(isset($data['id'])){                 $pre .= '<2 class='wrap'>';                 $spost .= '</2>';                  $stack[] = $things[$data['id']];             }              $spost .= '</1>';             $post .= $spost;         }     }      return $pre . $post; }