​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 xmlDoc = xml.responseXML;
    var x = xmlDoc.getElementsByTagName('book');
    x[0].setAttribute("category","烹饪");
    document.getElementById("demo").innerHTML =
    x[0].getAttribute("category");
}
</script>
​
</body>
</html>
​