php 无限极递归分类

<?php 

		$array = array(
		array(‘id‘ => 1, ‘pid‘ => 0, ‘name‘ => ‘河北省‘),
		array(‘id‘ => 2, ‘pid‘ => 0, ‘name‘ => ‘北京市‘),
		array(‘id‘ => 3, ‘pid‘ => 1, ‘name‘ => ‘邯郸市‘),
		array(‘id‘ => 4, ‘pid‘ => 2, ‘name‘ => ‘朝阳区‘),
		array(‘id‘ => 5, ‘pid‘ => 2, ‘name‘ => ‘通州区‘),
		array(‘id‘ => 6, ‘pid‘ => 4, ‘name‘ => ‘望京‘),
		array(‘id‘ => 7, ‘pid‘ => 4, ‘name‘ => ‘酒仙桥‘),
		array(‘id‘ => 8, ‘pid‘ => 3, ‘name‘ => ‘永年区‘),
		array(‘id‘ => 9, ‘pid‘ => 1, ‘name‘ => ‘武安市‘),
		);
		// echo "<pre>";
		// var_dump($array);
		function getTree($array, $pid =0, $level = 0){

        //声明静态数组,避免递归调用时,多次声明导致数组覆盖
        static $list = [];
        foreach ($array as $key => $value){
            //第一次遍历,找到父节点为根节点的节点 也就是pid=0的节点
            if ($value[‘pid‘] == $pid){
                //父节点为根节点的节点,级别为0，也就是第一级
                $value[‘level‘] = $level;
                //把数组放到list中
                $list[] = $value;
                //把这个节点从数组中移除,减少后续递归消耗
                unset($array[$key]);
                //开始递归,查找父ID为该节点ID的节点,级别则为原级别+1
                getTree($array, $value[‘id‘], $level+1);

            }
        }
        return $list;
    }

    /*
     * 获得递归完的数据,遍历生成分类
     */
    $array = getTree($array);

    foreach($array as $value){
       echo str_repeat(‘--‘, $value[‘level‘]), $value[‘name‘].‘<br />‘;
    }
    

?>