获取JSON的第一个条目

Question

I have this JSON in a URL:

{"success":true,"rgInventory":{"6073259621":{"id":"6073259621","classid":"1660549198","instanceid":"188530139","amount":"1","pos":1}}}

I need obtain the first entry after rgInventory. The problem is the problem is that suppose that I don't know that there are "6073259621". How I can obtain it without know what there?

I try this but don't work:

$obj = json_decode(file_get_contents($url), true);
$obj2 = json_decode(json_encode($obj['rgInventory']), true);
$obj3 = json_decode(json_encode($obj2), true); 
echo $obj3;

Answer 1

Here's a simple way to get the key and the value (array) using each():

$data = json_decode(file_get_contents($url), true);

list($key, $val) = each($data['rgInventory']);

echo $key;
print_r($val);

Yields:

6073259621
Array
(
    [id] => 6073259621
    [classid] => 1660549198
    [instanceid] => 188530139
    [amount] => 1
    [pos] => 1
)

But I just noticed that the id is the same as the key, so not really needed.