求助关于淘宝api返回xml简单对象提取为数组的问题？
一、通过淘宝api获得某个商品信息，得到如下xml对象
simplexmlelement object ( [item] => simplexmlelement object ( [auction_point] => 5 [detail_url] => http://item.taobao.com/item.htm?id=42234097497&spm=2014.23062087.0.0 [item_imgs] => simplexmlelement object ( [@attributes] => array ( [list] => true ) [item_img] => array ( [0] => simplexmlelement object ( [id] => 0 [position] => 0 [url] => http://img01.taobaocdn.com/bao/uploaded/i1/tb1gy_ggpxxxxx8apxxxxxxxxxx_!!0-item_pic.jpg ) [1] => simplexmlelement object ( [id] => 17030079984 [position] => 1 [url] => http://img01.taobaocdn.com/bao/uploaded/i1/tb1.lkwgxxxxxxyapxxxxxxxxxx_!!0-item_pic.jpg ) [2] => simplexmlelement object ( [id] => 17030079985 [position] => 2 [url] => http://img03.taobaocdn.com/bao/uploaded/i3/1703225540/tb25ut7avxxxxxuxpxxxxxxxxxx_!!1703225540.jpg ) [3] => simplexmlelement object ( [id] => 17030079986 [position] => 3 [url] => http://img02.taobaocdn.com/bao/uploaded/i2/1703225540/tb2.3r6avxxxxx3xpxxxxxxxxxx_!!1703225540.jpg ) [4] => simplexmlelement object ( [id] => 17030079987 [position] => 4 [url] => http://img01.taobaocdn.com/bao/uploaded/i1/1703225540/tb2dv__avxxxxxlxpxxxxxxxxxx_!!1703225540.jpg ) ) ) [nick] => 雪荞旗舰店 [num_iid] => 42234097497 [price] => 88.00 [title] => 【买1送1】雪荞乌金红滇红茶叶礼云南凤庆特级密香功夫红茶包邮 ) ) array ( [iserror] => 1 [store_type] => simplexmlelement object ( [0] => 5 ) [item_link] => simplexmlelement object ( [0] => http://item.taobao.com/item.htm?id=42234097497&spm=2014.23062087.0.0 ) [img] => simplexmlelement object ( [0] => http://img01.taobaocdn.com/bao/uploaded/i1/tb1gy_ggpxxxxx8apxxxxxxxxxx_!!0-item_pic.jpg ) [item_id] => simplexmlelement object ( [0] => 42234097497 ) [item_title] => simplexmlelement object ( [0] => 【买1送1】雪荞乌金红滇红茶叶礼云南凤庆特级密香功夫红茶包邮 ) [store_id] => simplexmlelement object ( [0] => 雪荞旗舰店 ) [market_price] => simplexmlelement object ( [0] => 88.00 ) )
二、赋值给$getdata
三、通过以下方法取值 
$result = array
(
'iserror' =>true,
'store_type' =>$getdata->item->auction_point,
'item_link' =>$getdata->item->detail_url,
'img' =>$getdata->item->item_imgs->item_img[0]->url,
'item_id' =>$getdata->item->num_iid,
'item_title' =>$getdata->item->title,
'store_id' =>$getdata->item->nick,
'market_price' =>$getdata->item->price
);
为何得到的值是一个不正确的json对象
{iserror:true,store_type:{0:5},item_link:{0:http:\/\/item.taobao.com\/item.htm?id=42234097497&spm=2014.23062087.0.0},img:{0:http:\/\/img01.taobaocdn.com\/bao\/uploaded\/i1\/tb1gy_ggpxxxxx8apxxxxxxxxxx_!!0-item_pic.jpg},item_id:{0:42234097497},item_title:{0:【买1送1】雪荞乌金红滇红茶叶礼云南凤庆特级密香功夫红茶包邮},store_id:{0:雪荞旗舰店},market_price:{0:88.00}}
四、我想要得到的是
,store_type:5,,而不是store_type:{0:5} 请大神帮忙为感！
------解决思路----------------------
echo $getdata->asxml();
不就得到了吗？