驼峰对象转下划线数组和下划线数组转驼峰对象

    /***
     * @param $fields 下划线数组
     * @return \stdClass
     */
    public static function underLineArrTOCamel($fields)
    {

        $newObj = new \stdClass();
        if(!is_array($fields) || !$fields) return null;
        foreach ($fields as $key => $v) {
            $keyTmp = array_reduce(explode('_',$key), function($v1, $v2) {
                return ucfirst($v1).ucfirst($v2);
            });
            $keyTmp = lcfirst($keyTmp);
            $newObj->$keyTmp = $v;
            unset($fields[$key]);
        }
        return $newObj;
    }