simplexml_load_string获取xml节点里的属性值

http://stackoverflow.com/questions/14359658/get-xml-attribute-using-simplexml-load-string

问：

I am using a few third party APIs which returns errors via xml in the following form:

<xml>
<status>0</status>
<error code="111">Error message text goes here.</error>
</xml>

Using simplexml_load_string in PHP I can easily get the status 0 and the error message text but I cannot find a means of retrieving the code="111" value from the <error code="111">. It seems to get dropped by SimpleXML.

<?php
    $bytesRead = file_get_contents('http://api.....');
    $xml = simplexml_load_string($bytesRead);
    echo '<pre>'; print_r($xml); echo '</pre>';
?>

Outputs

SimpleXMLElement Object
(
    [status] => 0
    [error] => Error message text goes here.
)

Am I missing something? Is there a way to obtain this value or can someone suggest another method to get this?

回答：

So far, we have only covered the work of reading element names and their values. SimpleXML can also access element attributes. Access attributes of an element just as you would elements of an array.

Example:

$x = '<xml>
<status>0</status>
<error code="111">Error message text goes here.</error>
</xml>';
$attributeObject = simplexml_load_string($x)->error['code'];
print_r($attributeObject);
print_r((string) $attributeObject);

Program Output (Demo)

SimpleXMLElement Object
(
    [0] => 111
)
111