php object to xml

1<?php
2$array = array('hello' => 'world', 'good' => 'morning');
3
4$xml = simplexml_load_string("<?xml version='1.0' encoding='utf-8'?><foo />");
5foreach ($array as $k=>$v) {
6  $xml->addChild($k, $v);
7}
8?>
9