📄 xhtml_html.asp
字号:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang="en-US" xml:lang="en-US" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>XHTML vs HTML</title>
<link rel="shortcut icon" href="../favicon.ico" type="image/x-icon" />
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<meta name="Keywords" content="xml,tutorial,html,dhtml,css,xsl,xhtml,javascript,asp,ado,vbscript,dom,sql,colors,soap,php,authoring,programming,training,learning,beginner's guide,primer,lessons,school,howto,reference,examples,samples,source code,tags,demos,tips,links,FAQ,tag list,forms,frames,color table,w3c,cascading style sheets,active server pages,dynamic html,internet,database,development,Web building,Webmaster,html guide" />
<meta name="Description" content="Free HTML XHTML CSS JavaScript DHTML XML DOM XSL XSLT RSS AJAX ASP ADO PHP SQL tutorials, references, examples for web building." />
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" content="no-cache" />
<link rel="stylesheet" type="text/css" href="../stdtheme.css" />
<script type="text/javascript">
var gaJsHost = (("https:" == document.location.protocol) ? "../../https@ssl./default.htm" : "../../www./default.htm");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
var pageTracker = _gat._getTracker("UA-3855518-1");
pageTracker._initData();
pageTracker._trackPageview();
</script>
</head>
<body>
<a name="top"></a>
<table cellpadding="0" cellspacing="0" width="100%" bgcolor="#808080">
<tr>
<td width="234" valign="top">
<a href="../default.htm"><img src="../images/w3default80.jpg" border="0" alt="W3Schools" /></a>
</td>
<th valign="middle" align="left" class="right">
<script type="text/javascript"><!--
google_ad_client = "pub-3440800076797949";
/*txtimg*/
google_ad_slot = "5330033957";
google_ad_width = 728;
google_ad_height = 90;
//-->
</script>
<script type="text/javascript" src="../../pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
<noscript>
<a href="../default.asp" target="_blank"><img src="../banners/w6.gif" border="0" alt="W3Schools" /></a>
</noscript>
<br /></th>
</tr>
</table>
<table style="margin-left:1px" width="800px" border="0" cellpadding="0" cellspacing="2">
<tr>
<td width="137" class="content" valign="top"><br />
<a class="left" href="../default.asp" target="_top">
<img src="../images/homeicon.gif" border="0" alt="home" /></a>
<a class="left" href="../default.asp" target="_top">
<b>HOME</b></a>
<br /><br />
<b>XHTML Tutorial</b><br />
<a class="left" target="_top" href="default.asp" >XHTML HOME</a><br />
<a class="left" target="_top" href="xhtml_intro.asp" >XHTML Introduction</a><br />
<a class="left" target="_top" href="xhtml_why.asp" >XHTML Why</a><br />
<a class="left" target="_top" href="xhtml_html.asp" style='font-weight:bold;'>XHTML v HTML</a><br />
<a class="left" target="_top" href="xhtml_syntax.asp" >XHTML Syntax</a><br />
<a class="left" target="_top" href="xhtml_dtd.asp" >XHTML DTD</a><br />
<a class="left" target="_top" href="xhtml_howto.asp" >XHTML HowTo</a><br />
<a class="left" target="_top" href="xhtml_validate.asp" >XHTML Validation</a><br />
<a class="left" target="_top" href="xhtml_modules.asp" >XHTML Modules</a><br />
<a class="left" target="_top" href="xhtml_standardattributes.asp" >XHTML Attributes</a><br />
<a class="left" target="_top" href="xhtml_eventattributes.asp" >XHTML Events</a><br />
<a class="left" target="_top" href="xhtml_summary.asp" >XHTML Summary</a><br />
<br />
<b>Quiz/Exam</b>
<br />
<a class="left" target="_top" href="xhtml_quiz.asp" >XHTML Quiz</a><br />
<a class="left" target="_top" href="xhtml_exam.asp" >XHTML Exam</a><br />
<br />
<b>References</b><br />
<a class="left" target="_top" href="../tags/default.asp">XHTML Tag List</a><br />
<a class="left" target="_top" href="../tags/ref_standardattributes.asp">XHTML Attributes</a><br />
<a class="left" target="_top" href="../tags/ref_eventattributes.asp">XHTML Events</a><br />
<a class="left" target="_top" href="../tags/ref_colornames.asp">XHTML Colornames</a><br />
<a class="left" target="_top" href="../tags/ref_ascii.asp">XHTML ASCII</a><br />
<a class="left" target="_top" href="../tags/ref_entities.asp">XHTML Entities</a><br />
<a class="left" target="_top" href="../tags/ref_urlencode.asp">XHTML URL Encode</a><br />
<a class="left" target="_top" href="../tags/ref_httpmessages.asp">HTTP Messages</a><br /><br />
<b>Selected Reading</b><br />
<a class="left" target="_top" href="../browsers/browsers_stats.asp">Web Statistics</a><br />
<a class="left" target="_top" href="../site/site_glossary.asp">Web Glossary</a><br />
<a class="left" target="_top" href="../hosting/default.asp">Web Hosting</a><br />
<a class="left" target="_top" href="../quality/default.asp">Web Quality</a><br /><br />
<a class="left" target="_top" href="../forum/default.asp">W3Schools Forum</a><br /><br />
<a class="left" target="_top" href="../about/about_helping.asp">Helping W3Schools</a><br /><br />
<script type="text/javascript"><!--
google_ad_client = "pub-3440800076797949";
/*LeftLinkUnit*/
google_ad_slot = "4854527104";
google_ad_width = 120;
google_ad_height = 90;
//-->
</script>
<script type="text/javascript"
src="../../pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
</td>
<td valign="top">
<table style="border: 1px solid gray" width="100%" bgcolor="#FFFFFF" border="0" cellpadding="5" cellspacing="0">
<tr>
<td>
<h1>Differences Between XHTML And HTML</h1>
<a href="xhtml_why.asp"><img border="0" src="../images/btn_previous.gif" width="100" height="20" alt="Previous" /></a>
<a href="xhtml_syntax.asp"><img border="0" src="../images/btn_next.gif" width="100" height="20" alt="Next" /></a>
<hr />
<p class="intro">You can prepare yourself for XHTML by starting to write strict HTML.</p>
<hr />
<h2>How To Get Ready For XHTML</h2>
<p>XHTML is not very different from
the HTML 4.01 standard.</p>
<p>So, bringing your code up to the 4.01 standard is a good start. Our
complete <a href="../html/html_reference.asp">HTML 4.01 reference</a> can help
you with that.</p>
<p>In addition, you should start NOW to write your HTML
code in lowercase letters, and NEVER skip ending tags
(like </p>).</p>
<p>Happy coding!</p>
<hr />
<h2>The Most Important Differences:</h2>
<ul>
<li>XHTML elements must be <b> properly nested</b></li>
<li>XHTML elements must always be <b> closed</b></li>
<li>XHTML elements must be in <b> lowercase</b></li>
<li>XHTML documents must have <b>one root element</b></li>
</ul>
<hr />
<h2><b>XHTML Elements Must Be Properly Nested</b></h2>
<p>In HTML, some elements can be improperly nested within each other, like this:</p>
<table width="100%" border="1" class="ex" cellspacing="0"><tr><td>
<pre><b><i>This text is bold and italic</b></i></pre>
</td></tr></table>
<p>In XHTML, all elements must be properly nested within each other, like this:</p>
<table width="100%" border="1" class="ex" cellspacing="0"><tr><td>
<pre><b><i>This text is bold and italic</i></b></pre>
</td></tr></table>
<p><b>Note:</b> A common mistake with nested lists, is to forget that the
inside list must be within <li> and </li> tags.</p>
<p>This is wrong:</p>
<table width="100%" border="1" class="ex" cellspacing="0">
<tr>
<td>
<pre><ul>
<li>Coffee</li>
<li>Tea
<ul>
<li>Black tea</li>
<li>Green tea</li>
</ul>
<li>Milk</li>
</ul></pre>
</td>
</tr>
</table>
<p>This is correct:</p>
<table width="100%" border="1" class="ex" cellspacing="0">
<tr>
<td>
<pre><ul>
<li>Coffee</li>
<li>Tea
<ul>
<li>Black tea</li>
<li>Green tea</li>
</ul>
</li>
<li>Milk</li>
</ul></pre>
</td>
</tr>
</table>
<p>Notice that we have inserted a </li> tag after the </ul> tag
in the "correct" code example.</p>
<hr />
<h2>XHTML Elements Must Always Be Closed</h2>
<p><b>Non-empty elements must have an end
tag.</b></p>
<p>This is wrong:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table1"><tr><td>
<pre><p>This is a paragraph
<p>This is another paragraph</pre>
</td></tr></table>
<p>This is correct:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table2"><tr><td>
<pre><p>This is a paragraph</p>
<p>This is another paragraph</p></pre>
</td></tr></table>
<br />
<hr />
<h2>Empty Elements Must Also Be Closed</h2>
<p><b>Empty elements must either have an end tag or the start tag must end with <code>/></code>.</b></p>
<p>This is wrong:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table3"><tr><td>
<pre>A break: <br>
A horizontal rule: <hr>
An image: <img src="happy.gif" alt="Happy face"></pre>
</td></tr></table>
<p>This is correct:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table4"><tr><td>
<pre>A break: <br />
A horizontal rule: <hr />
An image: <img src="happy.gif" alt="Happy face" /></pre>
</td></tr></table>
<br />
<hr />
<h2>XHTML Elements Must Be In Lower Case</h2>
<p>The XHTML specification defines that the tag names and attributes need to be
lower case. </p>
<p>This is wrong:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table5"><tr><td>
<pre><BODY>
<P>This is a paragraph</P>
</BODY></pre>
</td></tr></table>
<p>This is correct:</p>
<table width="100%" border="1" class="ex" cellspacing="0" id="table6"><tr><td>
<pre><body>
<p>This is a paragraph</p>
</body></pre>
</td></tr></table>
<br />
<hr />
<h2><b>XHTML Documents Must Have One Root Element</b></h2>
<p>All XHTML elements must be nested within the <html> root element. All
other elements can have sub (children) elements. Sub elements must be in pairs
and correctly nested within their parent element. The basic document structure
is:</p>
<table width="100%" border="1" class="ex" cellspacing="0"><tr><td>
<pre><html>
<head> ... </head>
<body> ... </body>
</html></pre>
</td></tr></table>
<br />
<hr />
<a href="xhtml_why.asp"><img border="0" src="../images/btn_previous.gif" width="100" height="20" alt="Previous" /></a>
<a href="xhtml_syntax.asp"><img border="0" src="../images/btn_next.gif" width="100" height="20" alt="Next" /></a>
<br />
<hr />
<!-- **** SPOTLIGHTS 1 **** -->
<iframe src="../banners/aspallframe.asp" height="110" width="485"
marginwidth="0" marginheight="0" frameborder="0" scrolling="no">
Your browser does not support inline frames or is currently configured not to display inline frames.
</iframe>
<hr />
<!-- **** SPOTLIGHTS 2 **** -->
<!-- **** SPOTLIGHTS 3 **** -->
<table cellpadding="0" cellspacing="0"><tr><td width="72"></td><td>
<script type="text/javascript"><!--
google_ad_client = "pub-3440800076797949";
/*txt*/
google_ad_slot = "1699448869";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="../../pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
</td></tr></table>
<hr />
<center>
<iframe style="background-color:#ffffff" src="../banners/aspallbannerframe.asp" height="60" width="468" marginwidth="0" marginheight="0" frameborder="0" scrolling="no">
Your browser does not support inline frames or is currently configured not to display inline frames.
</iframe>
</center>
<hr />
<table>
<tr>
<td><img src="../images/diploma.jpg" alt="diploma" /></td>
<td> </td>
<td valign="top">
<h2>Get Your Diploma!</h2>
<p>W3Schools' Online Certification Program is the perfect solution for busy
professionals who need to balance work, family, and career building.</p>
<p>The <a href="../cert/default.asp">HTML Certificate</a> is for developers who want to document their knowledge of HTML, XHTML, and CSS.</p>
<p>The <a href="../cert/default.asp">ASP Certificate</a> is for developers who want to document their knowledge of ASP, SQL, and ADO.</p>
</td>
</tr>
</table>
<br />
<hr />
<!-- **** END SPOTLIGHTS **** -->
</td></tr>
<tr><td>
<p>Jump to: <a href="#top" target="_top"><b>Top of Page</b></a>
or <a href="../default.asp" target="_top"><b>HOME</b></a> or
<a href='xhtml_html.asp@output=print' target="_blank">
<img src="../images/print.gif" alt="Printer Friendly" border="0" />
<b>Printer friendly page</b></a></p>
<p>W3Schools provides material for training only. We do not warrant the correctness of its contents.
The risk from using it lies entirely with the user.
While using this site, you agree to have read and accepted our
<a href="../about/about_copyright.asp">terms of use</a> and
<a href="../about/about_privacy.asp">privacy policy</a>.
</p>
<p><a href="../about/about_copyright.asp">Copyright 1999-2008</a> by Refsnes Data. All Rights Reserved.</p>
<table border="0" width="100%" cellspacing="0" cellpadding="0"><tr>
<td width="60%" align="left">
<a href="../../validator.w3.org/check@uri=referer" target="_blank">
<img src="../images/vxhtml.gif" alt="Validate" width="88" height="31" border="0" /></a>
<a href="../../jigsaw.w3.org/css-validator/check@uri=referer" target="_blank">
<img src="../images/vcss.gif" alt="Validate" width="88" height="31" border="0" /></a>
<a href="../../www.w3.org/WAI/WCAG1A-Conformance" title="Explanation of Level A Conformance" target="_blank">
<img src="../images/wai.gif" alt="W3C-WAI level A conformance icon" width="88" height="31" border="0" /></a>
</td>
<td>
<a href="xhtml_howto.asp" target="_top">W3Schools was converted to XHTML in December 1999</a>
</td></tr>
</table>
</td></tr>
</table>
</td>
<td width="145" align="center" valign="top">
<iframe style="background-color:#f1f1f1" src="../banners/rightcolumn.asp@secid=xhtml" height="1500" width="147"
marginwidth="0" marginheight="0" frameborder="0" scrolling="no">
</iframe>
</td>
</tr></table>
</body>
</html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -