How to use iteration to extract a hierarchical array (i.e. a multi-dimensional array)?

I want this effect, using iteration

I have this effect now, how can I make the array taken out hierarchical?

How to modify the current code? Or give me some ideas

<code>//迭代调用子孙树
function node_merge($node,$access,$parent = 0){
    $task = array($parent) ; //任务表
    $arr = array(); //返回数据
    while (!empty($task)) {
        $flag = false; //声明标识符
        foreach ($node as $k=> $v) {

            if($v['pid'] == $parent){
                if (isset($node[$parent])) {
                    $arr[] = $v;
                }
                // $arr[] = $v; //将找到的栏目存进$arr,等待返回
                array_push($task, $v['id']);//将最新的地区存入任务栈,只要task还有任务,循环会继续.
                $parent = $v['id'];//将当前id存入$parent
                unset($node[$k]); //把找到的单元unset掉

                $flag = true; //说明找到了子栏目

            }

        
    }
        //如果flsg为false,就代表找不到已找不到子栏目了,可以将最后的单元pop掉然后继续循环了.
        if ($flag == false) {
            array_pop($task); //弹出任务表
                $parent = end($task); //把找到的单元unset掉
            }
        
    }
    
    return $arr;
}
</code>

Reply content:

I want this effect, using iteration

I have this effect now, how can I make the array taken out hierarchical?

How to modify the current code? Or give me some ideas

<code>//迭代调用子孙树
function node_merge($node,$access,$parent = 0){
    $task = array($parent) ; //任务表
    $arr = array(); //返回数据
    while (!empty($task)) {
        $flag = false; //声明标识符
        foreach ($node as $k=> $v) {

            if($v['pid'] == $parent){
                if (isset($node[$parent])) {
                    $arr[] = $v;
                }
                // $arr[] = $v; //将找到的栏目存进$arr,等待返回
                array_push($task, $v['id']);//将最新的地区存入任务栈,只要task还有任务,循环会继续.
                $parent = $v['id'];//将当前id存入$parent
                unset($node[$k]); //把找到的单元unset掉

                $flag = true; //说明找到了子栏目

            }

        
    }
        //如果flsg为false,就代表找不到已找不到子栏目了,可以将最后的单元pop掉然后继续循环了.
        if ($flag == false) {
            array_pop($task); //弹出任务表
                $parent = end($task); //把找到的单元unset掉
            }
        
    }
    
    return $arr;
}
</code>

It shouldn’t be so complicated~
Using recursion can easily accomplish such a task:

Recursion

<code class="php">function parseTree($tree, $root = null) {
    $nested = array();
    foreach($tree as $index => $child) {
        if($child['pid'] == $root) {
            unset($tree[$index]);
            $child['children'] = parseTree($tree, $child['id']);
            $nested[] = $child;
        }
    }
    return empty($nested) ? null : $nested;
}</code>

Iteration

<code class="php">function parseTree($rows) {
  $rows = array_column ( $rows, null, 'id' );
  foreach ( $rows as $key => $val ) {
      if ( $val ['pid'] ) {
          if ( isset ( $rows [$val ['pid']] )) {
              $rows [$val ['pid']]['children'][] = &$rows [$key];
          }
      }
  }

  foreach ( $rows as $key => $val ) {
      if ( $val ['pid'] ) unset ( $rows [$key] );
  }

  return $rows;
}</code>