w3schools
  
HOME HTML CSS XML JAVASCRIPT ASP PHP SQL MORE...   References Examples Forum About

HTML DOM Node Tree

« Previous Next Chapter »

The HTML DOM views a HTML document as a node-tree.

All the nodes in the tree have relationships to each other.


The HTML DOM Node Tree

The HTML DOM views a HTML document as a tree-structure. The tree structure is called a node-tree.

All nodes can be accessed through the tree. Their contents can be modified or deleted, and new elements can be created.

The node tree below shows the set of nodes, and the connections between them. The tree starts at the root node and branches out to the text nodes at the lowest level of the tree:

HTML DOM Node tree


Node Parents, Children, and Siblings

The nodes in the node tree have a hierarchical relationship to each other.

The terms parent, child, and sibling are used to describe the relationships. Parent nodes have children. Children on the same level are called siblings (brothers or sisters).

  • In a node tree, the top node is called the root
  • Every node, except the root, has exactly one parent node
  • A node can have any number of children
  • A leaf is a node with no children
  • Siblings are nodes with the same parent

The following image illustrates a part of the node tree and the relationship between the nodes:

Node tree

Look at the following HTML fragment:

<html>
  <head>
    <title>DOM Tutorial</title>
  </head>
  <body>
    <h1>DOM Lesson one</h1>
    <p>Hello world!</p>
  </body>
</html>

From the HTML above:

  • The <html> node has no parent node; it is the root node
  • The parent node of the <head> and <body> nodes is the <html> node
  • The parent node of the "Hello world!" text node is the <p> node

and:

  • The <html> node has two child nodes; <head> and <body>
  • The <head> node has one child node; the <title> node
  • The <title> node also has one child node; the text node "DOM Tutorial"
  • The <h1> and <p> nodes are siblings, and both child nodes of <body>

First Child - Last Child

From the HTML above:

  • the <head> element is the first child of the <html> element, and the <body> element is the last child of the <html> element
  • the <h1> element is the first child of the <body> element, and the <p> element is the last child of the <body> element

« Previous Next Chapter »


Make your web applications look like a million bucks

FusionCharts   

Most web applications today use boring methods to present data to their viewers using grids or simple HTML tables. FusionCharts induces "life" into the web applications by converting monotonous data into lively charts, gauges & maps.

FusionCharts works with all technologies like ASP, ASP.NET, PHP, ColdFusion, Ruby on Rails, JSP, HTML pages etc. and connects to any database to render animated & interactive charts. It takes less than 15 minutes and no expertise whatsoever to build your first chart and just a glance of it to captivate your audience. This fact is endorsed by our 12,000 customers and 150,000 users which include a majority of the Fortune 500 companies. And yeah, your applications could look like a million bucks by spending just $69.

So go ahead, download your copy of FusionCharts and start "wow-ing" your customers now!



W3Schools Certification

W3Schools' Online Certification Program

The perfect solution for professionals who need to balance work, family, and career building.

More than 4000 certificates already issued!

The HTML Certificate documents your knowledge of HTML, XHTML, and CSS.

The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.

The XML Certificate documents your knowledge of XML, XML DOM and XSLT.

The ASP Certificate documents your knowledge of ASP, SQL, and ADO.

The PHP Certificate documents your knowledge of PHP and SQL (MySQL).

WEB HOSTING
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
FREE Web Hosting
Top Web Hosting
Windows Hosting
WEB BUILDING
XML Editor – Free Trial!
FREE Flash Website
FREE Web Templates
FLIGHT TICKETS
Find the cheapest flight
to any destination now!
EDUCATION
US Web Design Schools
HTML Certification
JavaScript Certification
XML Certification
PHP Certification
ASP Certification
STATISTICS
Browser Statistics
Browser OS
Browser Display