​x
 
<!DOCTYPE html>
<html>
<body>
​
<p id="demo"></p>
​
<script>
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
        myFunction(this);
    }
};
xhttp.open("GET", "/demo/xml/books.xml", true);
xhttp.send();
​
function myFunction(xml) {
    var x, y, z, i, xLen, newAtt, xmlDoc, txt;
    xmlDoc = xml.responseXML;
    x = xmlDoc.getElementsByTagName('book');
    xLen = x.length;
    for (i = 0; i < xLen; i++) { 
        newAtt = xmlDoc.createAttribute("edition");
        newAtt.value = "第一版";
        x[i].setAttributeNode(newAtt);
    }
    // 输出所有 "edition" 属性值
    txt = "";
    for (i = 0; i < x.length; i++) { 
        txt += "Edition: " + x[i].getAttribute("edition") + "<br>";
    }
    document.getElementById("demo").innerHTML = txt; 
}
</script>
​
</body>
</html>
​