​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, newComment, xmlDoc;
    xmlDoc = xml.responseXML;
    newComment = xmlDoc.createComment("2024 年 2 月修订");
    x = xmlDoc.getElementsByTagName("book")[0];
    x.appendChild(newComment);
    document.getElementById("demo").innerHTML = x.lastChild.nodeValue;
}
</script>
​
</body>
</html>
​