XML DOM insertBefore() Method

Definition and Usage

insertBefore() This method inserts a new child node before the existing child nodes.

This method returns the new child node.

Syntax

elementNode.insertBefore(new_node,existing_node)
Parameters Description
new_node Required. The node to be inserted.
existing_node Required. Existing node. The new node will be inserted before this node.

Example

The following code loads "books.xml" into xmlDoc, creates a new <book> node, and inserts it before the last <book> element:

var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
   if (this.readyState == 4 && this.status == 200) {
       myFunction(this);
   {}
};
xhttp.open("GET", "books.xml", true);
xhttp.send();
function myFunction(xml) {
    var xmlDoc = xml.responseXML;
    var newNode = xmlDoc.createElement("book");
    var x = xmlDoc.documentElement;
    var y = xmlDoc.getElementsByTagName("book");
    document.getElementById("demo").innerHTML =
    "Book elements before: " + y.length + "<br>";
    x.insertBefore(newNode, y[3]);
    document.getElementById("demo").innerHTML +=
    "Book elements after: " + y.length;
{}

Try It Yourself