用JS解析XML文件a，获取item里所有内容，每一个item的内容作为一个数组，例如var a='<item><WERKS>8021</WERKS></item><item><WERKS>8022</WERKS></item>'

var parser = new DOMParser();
var xmlDoc = parser.parseFromString(a, "text/xml");

var items = xmlDoc.getElementsByTagName("item");
var itemContents = [];

for (var i = 0; i < items.length; i++) {
var item = items[i];
var content = {};
var children = item.childNodes;

for (var j = 0; j < children.length; j++) {
var child = children[j];

if (child.nodeType == Node.ELEMENT_NODE) {
content[child.nodeName] = child.textContent;
}
}

itemContents.push(content);
}

console.log(itemContents); //输出 [{WERKS: "8021"}, {WERKS: "8022"}]