xml和php for循环在另一个for循环中

我有两个用expedia api更新的xml文件。我试图从一个xml文件中获取房间信息和房间代码，并在另一个xml文件中找到该房间代码，以检索必要的房间信息。但我似乎不知道该怎么做。以下是xml模式：

XML 1（hotel_request.XML）：

---

希望有人能帮助我。谢谢

你能把这些xml文件放在某个地方让人们看一下吗。

<RoomTypes size="3">
<RoomType roomCode="9995" roomTypeId="157240">
<description>Standard</description>
</RoomType>
</RoomTypes>

<rateCode>9995</rateCode>
<roomTypeCode>9995</roomTypeCode>
<rateDescription>Standard - Super Saver- No meals included</rateDescription>
<roomTypeDescription>Standard - Super Saver- No meals included</roomTypeDescription>

//Getting xml file and data

    $data = simplexml_load_file('hotel_request.xml'); 
    $info = $data->HotelSummary;
    //foreach loop to go through and echo out all rooms
    foreach($data->RoomTypes as $rooms):
        $roomCode = $rooms->RoomType['roomCode'];
        $roomName = $rooms->RoomType->description;
    endforeach;

//Now I need to go through this above loop and get the roomCode, then look for that roomCode in the second xml file and get all it's associated information. So this is what I tried which DID NOT work:
foreach($data->RoomTypes as $rooms):
    $roomCode = $rooms->RoomType['roomCode'];
    $roomName = $rooms->RoomType->description;

//Here is where I added in other file
$avail = simplexml_load_file('room_request.xml');

    foreach($avail->HotelRoomResponse->$roomCode as $rooms):
    $promo = $rooms->RateInfos->RateInfo->ChargeableRateInfo->NightlyRatesPerRoom->NightlyRate['promo'];

endforeach;
endforeach;