XML Tutorial

XML HOME XML Introduction XML How to use XML Tree XML Syntax XML Elements XML Attributes XML Namespaces XML Display XML HttpRequest XML Parser XML DOM XML XPath XML XSLT XML XQuery XML XLink XML Validator XML DTD XML Schema XML Server XML Examples XML Quiz XML Certificate


AJAX Introduction AJAX XMLHttp AJAX Request AJAX Response AJAX XML File AJAX PHP AJAX ASP AJAX Database AJAX Applications AJAX Examples


DOM Introduction DOM Nodes DOM Accessing DOM Node Info DOM Node List DOM Traversing DOM Navigating DOM Get Values DOM Change Nodes DOM Remove Nodes DOM Replace Nodes DOM Create Nodes DOM Add Nodes DOM Clone Nodes DOM Examples

XPath Tutorial

XPath Introduction XPath Nodes XPath Syntax XPath Axes XPath Operators XPath Examples

XSLT Tutorial

XSLT Introduction XSL Languages XSLT Transform XSLT <template> XSLT <value-of> XSLT <for-each> XSLT <sort> XSLT <if> XSLT <choose> XSLT Apply XSLT on the Client XSLT on the Server XSLT Edit XML XSLT Examples

XQuery Tutorial

XQuery Introduction XQuery Example XQuery FLWOR XQuery HTML XQuery Terms XQuery Syntax XQuery Add XQuery Select XQuery Functions


DTD Introduction DTD Building Blocks DTD Elements DTD Attributes DTD Elements vs Attr DTD Entities DTD Examples

XSD Schema

XSD Introduction XSD How To XSD <schema> XSD Elements XSD Attributes XSD Restrictions

XSD Complex

XSD Elements XSD Empty XSD Elements Only XSD Text Only XSD Mixed XSD Indicators XSD <any> XSD <anyAttribute> XSD Substitution XSD Example

XSD Data

XSD String XSD Date XSD Numeric XSD Misc XSD Reference

Web Services



DOM Node Types DOM Node DOM NodeList DOM NamedNodeMap DOM Document DOM Element DOM Attribute DOM Text DOM CDATA DOM Comment DOM XMLHttpRequest DOM Parser XSLT Elements XSLT/XPath Functions

XML DOM - Navigating Nodes

Nodes can be navigated using node relationships.



Navigating DOM Nodes

Accessing nodes in the node tree via the relationship between nodes, is often called "navigating nodes".

In the XML DOM, node relationships are defined as properties to the nodes:

  • parentNode
  • childNodes
  • firstChild
  • lastChild
  • nextSibling
  • previousSibling

The following image illustrates a part of the node tree and the relationship between nodes in books.xml:

Node tree

DOM - Parent Node

All nodes have exactly one parent node. The following code navigates to the parent node of <book>:


function myFunction(xml) {
var xmlDoc = xml.responseXML;
    var x = xmlDoc.getElementsByTagName("book")[0];
    document.getElementById("demo").innerHTML = x.parentNode.nodeName;
Try it Yourself »

Example explained:

  1. Load "books.xml" into xmlDoc
  2. Get the first <book> element
  3. Output the node name of the parent node of "x"

Avoid Empty Text Nodes

Firefox, and some other browsers, will treat empty white-spaces or new lines as text nodes, Internet Explorer will not.

This causes a problem when using the properties: firstChild, lastChild, nextSibling, previousSibling.

To avoid navigating to empty text nodes (spaces and new-line characters between element nodes), we use a function that checks the node type:

function get_nextSibling(n) {
    var y = n.nextSibling;
    while (y.nodeType! = 1) {
        y = y.nextSibling;
    return y;

The function above allows you to use get_nextSibling(node) instead of the property node.nextSibling.

Code explained:

Element nodes are type 1. If the sibling node is not an element node, it moves to the next nodes until an element node is found. This way, the result will be the same in both Internet Explorer and Firefox.

Get the First Child Element

The following code displays the first element node of the first <book>:


<!DOCTYPE html>

<p id="demo"></p>

var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
};"GET", "books.xml", true);

function myFunction(xml) {
    var xmlDoc = xml.responseXML;
    var x = get_firstChild(xmlDoc.getElementsByTagName("book")[0]);
    document.getElementById("demo").innerHTML = x.nodeName;

//check if the first node is an element node
function get_firstChild(n) {
    var y = n.firstChild;
    while (y.nodeType != 1) {
        y = y.nextSibling;
    return y;



Try it Yourself »

Example explained:

  1. Load "books.xml" into xmlDoc
  2. Use the get_firstChild function on the first <book> element node to get the first child node that is an element node
  3. Output the node name of first child node that is an element node

More Examples

This example uses the lastChild() method and a custom function to get the last child node of a node

This example uses the nextSibling() method and a custom function to get the next sibling node of a node

This example uses the previousSibling() method and a custom function to get the previous sibling node of a node