Get an element from an array using xpath

I have the following SimpleXML object:

SimpleXMLElement Object
(
[@attributes] => Array
    (
        [status] => ok
    )

[a] => SimpleXMLElement Object
    (
        [b] => Array
            (
                [0] => SimpleXMLElement Object
                    (
                        [c] => Google
                        [d] => GOOG
                        [e] => http://www.google.com
                    )

                [1] => SimpleXMLElement Object
                    (
                        [c] => Yahoo
                        [d] => YHOO
                        [e] => http://www.yahoo.com
                    )

                开发者_JS百科[2] => SimpleXMLElement Object
                    (
                        [c] => Microsoft
                        [d] => MSFT
                        [e] => http://www.microsoft.com
                    )

Given d I want to get e - Since b is an array, is there any way to do this without looping through the entire array?

<stk status="ok">
<a>
  <b>
    <c>Yahoo</c>
    <d>YHOO</d>
    <e>http://www.yahoo.com</e>
  </b>

  <b>
    <c>Google</c>
    <d>GOOG</d>
    <e>http://www.google.com</e>
  </b>

  <b>
    <c>Microsoft</c>
    <d>MSFT</d>
    <e>http://www.microsoft.com</e>
  </b>
</a>
</stk>

You could use an XPath query asking for the e elements that are children of b elements having d elements with the text YHOO.

Remember that SimpleXMLElement::xpath() will return an array of elements, even if the XPath only finds one: hence $urls[0] to get the first (only) one.

$xml  = '<stk status="ok"><a><b><c>Yahoo</c><d>YHOO</d><e>http://www.yahoo.com</e></b><b><c>Google</c><d>GOOG</d><e>http://www.google.com</e></b><b><c>Microsoft</c><d>MSFT</d><e>http://www.microsoft.com</e></b></a></stk>';
$stk  = simplexml_load_string($xml);
$urls = $stk->xpath('/stk/a/b[d="YHOO"]/e');
$yhoo = (string) $urls[0];
echo $yhoo;

Iterate over all //d.

For each one, evaluate following-sibling::e[1].

I think that's what Marc B meant.