在编写 HTML 文档时,我们需要在文档的开头添加一个 DOCTYPE 声明,以告诉浏览器使用哪个 HTML 规范来解析文档。下面是一些常见的 HTML 有效 DOCTYPES:
HTML5 DOCTYPE
<!DOCTYPE html>
HTML5 是当前最新的 HTML 规范,使用这个 DOCTYPE 声明可以告诉浏览器使用 HTML5 规范来解析文档。
HTML 4.01 Strict DOCTYPE
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
HTML 4.01 Strict 是 HTML 4.01 规范中最严格的一个版本,使用这个 DOCTYPE 声明可以告诉浏览器使用 HTML 4.01 Strict 规范来解析文档。
HTML 4.01 Transitional DOCTYPE
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
HTML 4.01 Transitional 是 HTML 4.01 规范中较为宽松的一个版本,使用这个 DOCTYPE 声明可以告诉浏览器使用 HTML 4.01 Transitional 规范来解析文档。
XHTML 1.0 Strict DOCTYPE
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
XHTML 1.0 Strict 是一个基于 XML 的 HTML 规范,使用这个 DOCTYPE 声明可以告诉浏览器使用 XHTML 1.0 Strict 规范来解析文档。
以上是一些常见的 HTML 有效 DOCTYPES,根据文档的具体需求选择合适的 DOCTYPE 声明是非常重要的。
下面的表格列出了所有的 HTML5/HTML 4.01/XHTML 元素,以及它们会出现在什么文档类型 (!DOCTYPE) 中:
HTML 4.01 / XHTML 1.0 | |||
---|---|---|---|
Tag | HTML5 | Transitional | Strict |
<a> |
Yes | Yes | Yes |
<abbr> |
Yes | Yes | Yes |
<acronym> |
No | Yes | Yes |
<address> |
Yes | Yes | Yes |
<applet> |
No | Yes | No |
<area> |
Yes | Yes | Yes |
<article> |
Yes | No | No |
<aside> |
Yes | No | No |
<audio> |
Yes | No | No |
<b> |
Yes | Yes | Yes |
<base> |
Yes | Yes | Yes |
<basefont> |
No | Yes | No |
<bdi> |
Yes | No | No |
<bdo> |
Yes | Yes | Yes |
<big> |
No | Yes | Yes |
<blockquote> |
Yes | Yes | Yes |
<body> |
Yes | Yes | Yes |
<br> |
Yes | Yes | Yes |
<button> |
Yes | Yes | Yes |
<canvas> |
Yes | No | No |
<caption> |
Yes | Yes | Yes |
<center> |
No | Yes | No |
<cite> |
Yes | Yes | Yes |
<code> |
Yes | Yes | Yes |
<col> |
Yes | Yes | Yes |
<colgroup> |
Yes | Yes | Yes |
<command> |
Yes | No | No |
<datalist> |
Yes | No | No |
<dd> |
Yes | Yes | Yes |
<del> |
Yes | Yes | Yes |
<details> |
Yes | No | No |
<dfn> |
Yes | Yes | Yes |
<dir> |
No | Yes | No |
<div> |
Yes | Yes | Yes |
<dl> |
Yes | Yes | Yes |
<dt> |
Yes | Yes | Yes |
<em> |
Yes | Yes | Yes |
<embed> |
Yes | No | No |
<fieldset> |
Yes | Yes | Yes |
<figcaption> |
Yes | No | No |
<figure> |
Yes | No | No |
<font> |
No | Yes | No |
<footer> |
Yes | No | No |
<form> |
Yes | Yes | Yes |
<frame> |
No | No | No |
<frameset> |
No | No | No |
<h1> to <h6> |
Yes | Yes | Yes |
<head> |
Yes | Yes | Yes |
<header> |
Yes | No | No |
<hgroup> |
Yes | No | No |
<hr> |
Yes | Yes | Yes |
<html> |
Yes | Yes | Yes |
<i> |
Yes | Yes | Yes |
<iframe> |
Yes | Yes | No |
<img> |
Yes | Yes | Yes |
<input> |
Yes | Yes | Yes |
<ins> |
Yes | Yes | Yes |
<kbd> |
Yes | Yes | Yes |
<keygen> |
Yes | No | No |
<label> |
Yes | Yes | Yes |
<legend> |
Yes | Yes | Yes |
<li> |
Yes | Yes | Yes |
<link> |
Yes | Yes | Yes |
<map> |
Yes | Yes | Yes |
<mark> |
Yes | No | No |
<menu> |
Yes | Yes | No |
<meta> |
Yes | Yes | Yes |
<meter> |
Yes | No | No |
<nav> |
Yes | No | No |
<noframes> |
No | Yes | No |
<noscript> |
Yes | Yes | Yes |
<object> |
Yes | Yes | Yes |
<ol> |
Yes | Yes | Yes |
<optgroup> |
Yes | Yes | Yes |
<option> |
Yes | Yes | Yes |
<output> |
Yes | No | No |
<p> |
Yes | Yes | Yes |
<param> |
Yes | Yes | Yes |
<pre> |
Yes | Yes | Yes |
<progress> |
Yes | No | No |
<q> |
Yes | Yes | Yes |
<rp> |
Yes | No | No |
<rt> |
Yes | No | No |
<ruby> |
Yes | No | No |
<s> |
Yes | Yes | No |
<samp> |
Yes | Yes | Yes |
<script> |
Yes | Yes | Yes |
<section> |
Yes | No | No |
<select> |
Yes | Yes | Yes |
<small> |
Yes | Yes | Yes |
<source> |
Yes | No | No |
<span> |
Yes | Yes | Yes |
<strike> |
No | Yes | No |
<strong> |
Yes | Yes | Yes |
<style> |
Yes | Yes | Yes |
<sub> |
Yes | Yes | Yes |
<summary> |
Yes | No | No |
<sup> |
Yes | Yes | Yes |
<table> |
Yes | Yes | Yes |
<tbody> |
Yes | Yes | Yes |
<td> |
Yes | Yes | Yes |
<textarea> |
Yes | Yes | Yes |
<tfoot> |
Yes | Yes | Yes |
<th> |
Yes | Yes | Yes |
<thead> |
Yes | Yes | Yes |
<time> |
Yes | No | No |
<title> |
Yes | Yes | Yes |
<tr> |
Yes | Yes | Yes |
<track> |
Yes | No | No |
<tt> |
No | Yes | Yes |
<u> |
No | Yes | No |
<ul> |
Yes | Yes | Yes |
<var> |
Yes | Yes | Yes |
<video> |
Yes | No | No |
<wbr> |
Yes | No | No |