PHP handles parent-child level selection problem

/**
     * @param $data 操作的数组
     * @param string $fieldPri 唯一键名，如果是表则是表的主键
     * @param string $fieldPid 父ID键名
     * @param int $pid 一级PID的值
     * @param string $sid 子ID用于获得指定指ID的所有父ID
     * @param int $type 操作方式1=>返回多维数组,2=>返回一维数组,3=>得到指定子ID(参数$sid)的所有父
     * @param string $html 名称前缀，用于在视图中显示层次感的列表
     * @param int $level 不需要传参数（执行时调用）
     * @return array
     */
	private function channel($data, $fieldPri = 'cid', $fieldPid = 'pid', $pid = 0, $sid = null, $type = 2, $html = " ", $level = 1)
    {
        if (!$data) {
            return array();
        }
        switch ($type) {
            case 1:
                $arr = array();
                foreach ($data as $v) {
                    if ($v[$fieldPid] == $pid) {
                        $arr[$v[$fieldPri]] = $v;
                        $arr[$v[$fieldPri]]['html'] = str_repeat($html, $level - 1);
                        $arr[$v[$fieldPri]]["Data"] = self::channel($data, $fieldPri, $fieldPid, $v[$fieldPri], $sid, $type, $html, $level + 1);
                    }
                }
                return $arr;
            case 2:
                $arr = array();
                $id = 0;
                foreach ($data as $v) {
                    if ($v[$fieldPid] == $pid) {
                        $arr[$id] = $v;
                        $arr[$id]['level'] = $level;
                        $arr[$id]['html'] = str_repeat($html, $level - 1);
                        $sArr = self::channel($data, $fieldPri, $fieldPid, $v[$fieldPri], $sid, $type, $html, $level + 1);
                        $arr = array_merge($arr, $sArr);
                        $id = count($arr);
                    }
                }
                return $arr;
            case 3:
                static $arr = array();
                foreach ($data as $v) {
                    if ($v[$fieldPri] == $sid) {
                        $arr[] = $v;
                        $sArr = self::channel($data, $fieldPri, $fieldPid, $pid, $v[$fieldPid], $type, $html, $level + 1);
                        $arr = array_merge($arr, $sArr);
                    }
                }
                return $arr;
        }
    }

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The above has introduced the issue of parent-child level selection in PHP, including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.