从JavaScript和XML中的selectNodes获取属性？

var xmlString = "<root><item id='1'>Item 1</item><item id='2'>Item 2</item></root>";
var parser = new DOMParser();
var xmlDoc = parser.parseFromString(xmlString, "text/xml");
var items = xmlDoc.getElementsByTagName("item");
var attributes = [];
for (var i = 0; i< items.length; i++) {
  attributes.push(items[i].getAttribute("id"));
}
console.log(attributes); // 输出 ["1", "2"]

var xmlString = "<root><item id='1'>Item 1</item><item id='2'>Item 2</item></root>";
var parser = new DOMParser();
var xmlDoc = parser.parseFromString(xmlString, "text/xml");
var xpathResult = xmlDoc.evaluate("//item/@id", xmlDoc, null, XPathResult.ANY_TYPE, null);
var attributes = [];
var node;
while (node = xpathResult.iterateNext()) {
  attributes.push(node.nodeValue);
}
console.log(attributes); // 输出 ["1", "2"]