XHTML Syntax
Even though most structures of the XHTML are similar to
HTML, XHTML still requires some additional syntax rules to make it cleans.
The significant syntax are concluded as in the table below:
| Rule |
Description |
Example |
| Attribute Names Must Be In Lower Case |
As mention ealier that XHTML is case-sensitive.
All attibute name must be in lower case. Where as the attribute values
can be either upper or lower case. |
In HTML, we can use :
In XHTML, it must be :
|
| Attribute Values Must Be Quoted |
HTML does not require that a value assigned to an attribute
be enclosed in quotes. However, XHTML is very strict about this. If you
forget to enclose in quotes, then XHTML will completely ignore the attribute.
|
For example, in HTML we can use :
| <table border=0 cellpadding=5> |
In XHTML, it must be :
| <table border="0" cellpadding="5"> |
|
| No attribute may be minimized |
Having an attribute that
does not have a value assigned to it is illegal in XHTML. In other words,
no attribute minimization. |
For example, in HTML we can use :
In XHTML, it must be :
| <frame noresize="noresize" /> |
|
| "name" attribute is replaced
by "id" attribute |
To assign the name properties
with any elements, the attribute "id" replaces "name".
However, to avoid the incompatible for old browser, you can add the
attribute "name" if needed. |
For example, in HTML we can use :
| <img src="img.gif" name="pic1"> |
In XHTML, it must be :
| <img src="img.gif" id="pic1" /> |
|
| The XHTML mandatory elements |
As we known that, like
HTML, XHTML is a subset of the SGML. SGML use DTDs to define the context
of the language. All XHTML documents must have a DOCTYPE declaration
at the top (on the first line) of all XHTML code. The html, head and
body elements must be present, and the title must be present inside
the head element. |
This is the example of the XHTML mandatory elements :
<!DOCTYPE ....>
<html>
<head>
<title>This is Title</title>
</head>
<body>This is body</body>
</html>
|
|
The lang Attribute
|
The lang attribute is used to define the base language to be used for
displaying text and characters on a Website. The languages are designated
by a two letter code, such as "en" for English or "el"
for Greek. For U.S. English, we can assign as "en-us".
|
This is the example of language attribute :
<html xmlns="http://www.w3.org/1999/xhtml"
xml:lang="en" lang="en">
|
|
 |
 |
This tutorial is final project for INFSCI 2000, Fall 2004
Copyright 2004 School of Information Science, University of Pittsburgh