var dataXML = new XML('<?xml version="1.0" encoding="UTF-8"?><data><test id="2">テスト</test><test id="5">テスト</test></data>');

import mx.xpath.XPathAPI;
var results = XPathAPI.selectNodeList(dataXML, '*/data/test');
for( var i = 0; i < results.length ; i++ ){
	var idNum = results[i].attributes.id
	trace([idNum, typeof(idNum)]);
}

var dataXML = new XML('<?xml version="1.0" encoding="UTF-8"?><data><test id="2">テスト</test><test id="5">テスト</test></data>');

import com.xfactorstudio.xml.xpath.*
var results:Array = XPath.selectNodesAsNumber(dataXML, '*/data/test/@id')
for( var i = 0; i< results.length; i++ ){
	var idNum = results[i];
	trace( [idNum, typeof(idNum)] );
}