PHP 无限级分类方法

    /**
     * 无限级分类
     * @param array $items
     * @param int $pid
     * @param string $pidField
     * @param string $children
     * @return array
     */
    public static function TreeData(array $items, $pid = 0, $pidField = 'pid', $children = 'children')
    {
        $tree = [];

        foreach ($items as $key => $item) {
            if ($item[$pidField] == $pid) {
                $child = self::TreeData($items, $item['id'], $pidField);
                if (count($child)) {
                    $item[$children] =  $child;
                }
                $tree[] = $item;
            }
        }

        return $tree;
    }