XML DOM substringData() Method

Comment Object

Definition and Usage

substringData() Method to get a string from a comment node.

Syntax

substringData(start,length)
Parameter Description
start Required. Specifies the position at which to start extracting characters. The starting position is zero.
length Required. Specifies the number of characters to extract.

Example

The following code loads "books_comment.xml" into xmlDoc and retrieves the string "(Hardcover)" from the first comment element:

var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
   if (this.readyState == 4 && this.status == 200) {
       myFunction(this);
   }
};
xhttp.open("GET", "books_comment.xml", true);
xhttp.send();
function myFunction(xml) {
    var x, i, y, txt, xmlDoc;
    xmlDoc = xml.responseXML;
    txt = "";
    x = xmlDoc.getElementsByTagName("book")[0].childNodes;
    for (i = 0; i < x.length; i++) {
    // Only handle comment nodes
        if (x[i].nodeType == 8) {
            y = x[i].substringData(33, 11);
            txt += y + "<br>";
        }
    }
    document.getElementById("demo").innerHTML = txt;
}

Try It Yourself

In the above example, we used a loop and if test statements to ensure that we only handle comment nodes. The node type of comment nodes is 8.

Comment Object