INTRODUCTION
XHTML is a stricter and cleaner version of HTML
What is XHTML
- XHTML stands for EXtensible HyperText Markup Language
- XHTML is almost identical to HTML 4.01
- XHTML is a stricter and cleaner version of HTML
- XHTML is HTML defined as an XML application
- XHTML is a W3C Recommendation
SYNTAX
XHTML syntax rules
- Attribute names must be in lower case
- Attribute values must be quoted
- Attribute minimization is forbidden
- The id attribute replaces the name attribute
- The XHTML DTD defines mandatory elements
Attribute Names Must Be In Lower Case
This is wrong:
<table WIDTH="100%">
This is correct:
<table width="100%">
Attribute Values Must Be Quoted
This is wrong:
<table width=100%>
This is correct:
<table width="100%">
Attribute Minimization Is Forbidden
This is wrong:
<input checked> <input readonly>
This is correct:
<input checked="checked"> <input readonly="readonly">
The “id” attribute replaces the name attribute
HTML 4.01 defines a name attribute for the elements applet, frame, iframe, and img. In XHTML the name attribute is deprecated. Use id instead.
This is wrong:
<img src="picture.gif" name="pic1" />
This is correct:
<img src="picture.gif" id="pic1" />
Note: To interoperate with older browsers for a while, you should use both name and id, with identical attribute values, like this:
<img src="picture.gif" id="pic1" name="pic1"/>
IMPORTANT Compatibility Note:
To make your XHTML compatible with today’s browsers, you should add an extra space before the “/” symbol.
The Lang Attribute
The lang attribute applies to almost every XHTML element. It specifies the language of the content within an element.
If you use the lang attribute in an element, you must also add the xml:lang attribute, like this:
<div lang="no" xml:lang="no">Heia Norge!</div>
Mandatory XHTML Elements
All XHTML documents must have a DOCTYPE declaration. The html, head, title, and body elements must be present.
This is an XHTML document with a minimum of required tags:
<!DOCTYPE Doctype goes here> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Title goes here</title> </head> <body> </body> </html>
For more details visit www.w3schools.com