- var_dump: documentation ( source)
<?php
$writer = new SimpleXMLElement('<?xml version="1.0"?><MessageHeader><MessageThreadId>0000000022</MessageThreadId><MessageId>000000002201</MessageId><MessageSender><PartyId>PADPIDA2010071901R</PartyId><PartyName><FullName>RHAPSODY INTERNATIONAL, INC.</FullName></PartyName><TradingName>Premier Extra</TradingName></MessageSender><MessageRecipient><PartyId>SWAPFORSOCIETYID</PartyId><PartyName><FullName>SWAPFORSOCIETYNAME</FullName></PartyName></MessageRecipient><MessageCreatedDateTime>2014-06-30T09:35:57</MessageCreatedDateTime></MessageHeader>');
$messagerecipient = $writer->xpath('MessageRecipient');
//foreach($messagerecipient as $data){
//$data->PartyID = '1234';
//}
//$output = $writer->asXML();
//echo $output;
var_dump($messagerecipient);
?>