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

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XSD String XSD Date/Time XSD Numeric XSD Misc XSD Reference

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XML DOM - Accessing Nodes

With the DOM, you can access every node in an XML document.

Accessing Nodes

You can access a node in three ways:

  1. By using the getElementsByTagName() method
  2. By looping through (traversing) the nodes tree
  3. By navigating the node tree, using the node relationships

The getElementsByTagName() Method

getElementsByTagName() returns all elements with a specified tag name.




The following example returns all <title> elements under the x element:


Note that the example above only returns <title> elements under the x node. To return all <title> elements in the XML document use:


where xmlDoc is the document itself (document node).

DOM Node List

The getElementsByTagName() method returns a node list. A node list is an array of nodes.

x = xmlDoc.getElementsByTagName("title");

The <title> elements in x can be accessed by index number. To access the third <title> you can write::

y = x[2];

Note: The index starts at 0.

Try it Yourself

DOM Node List Length

The length property defines the length of a node list (the number of nodes).

You can loop through a node list by using the length property:


var x = xmlDoc.getElementsByTagName("title");

for (i = 0; i <x.length; i++) {
  // do something for each node
Try it Yourself »

Node Types

The documentElement property of the XML document is the root node.

The nodeName property of a node is the name of the node.

The nodeType property of a node is the type of the node.

You will learn more about the node properties in the next chapter of this tutorial.

Try it Yourself

Traversing Nodes

The following code loops through the child nodes, that are also element nodes, of the root node:


txt = "";
x = xmlDoc.documentElement.childNodes;

for (i = 0; i <x.length; i++) {
  // Process only element nodes (type 1)
  if (x[i].nodeType == 1) {
    txt += x[i].nodeName + "<br>";
Try it Yourself »

Example explained:

  1. Suppose you have loaded "books.xml" into xmlDoc
  2. Get the child nodes of the root element (xmlDoc)
  3. For each child node, check the node type. If the node type is "1" it is an element node
  4. Output the name of the node if it is an element node

Navigating Node Relationships

The following code navigates the node tree using the node relationships:


x = xmlDoc.getElementsByTagName("book")[0];
xlen = x.childNodes.length;
y = x.firstChild;

txt = "";
for (i = 0; i <xlen; i++) {
  // Process only element nodes (type 1)
  if (y.nodeType == 1) {
    txt += y.nodeName + "<br>";
  y = y.nextSibling;
Try it Yourself »

Example explained:

  1. Suppose you have loaded "books.xml" into xmlDoc
  2. Get the child nodes of the first book element
  3. Set the "y" variable to be the first child node of the first book element
  4. For each child node (starting with the first child node "y"):
  5. Check the node type. If the node type is "1" it is an element node
  6. Output the name of the node if it is an element node
  7. Set the "y" variable to be the next sibling node, and run through the loop again