nav
HTML 'nav' 标签表示页面的一部分, 用于提供导航链接。这些链接可以是页面内部的或者外部的。
导航部分的常见例子包括菜单、TOC 和索引。
例子
<!DOCTYPE html><html><head>  <meta http-equiv="content-type" content="text/html; charset=utf-8" />  <title>nav exmaple</title>  <style type="text/css">    html {background-color: white; }    nav { border-bottom: 1px solid black; }    .crumbs ol {      list-style-type: none;      padding-left: 0;    }    .crumb {      display: inline-block;    }    .crumb a::after {      display: inline-block;      color: #000;      content: ">";      font-size: 80%;      font-weight: bold;      padding: 0 3px;    }  </style></head><body><nav class="crumbs">  <ol>    <li class="crumb"><a href="#">Bikes</a></li>    <li class="crumb"><a href="#">BMX</a></li>    <li class="crumb">Jump Bike 3000</li>  </ol></nav><h1>Jump Bike 3000</h1><p>  This BMX bike is a solid step into the pro world. It looks as legit as it  rides and is built to polish your skills.</p></body></html>
用法说明
- 
不需要将所有链接都包含在
<nav>元素中。<nav>仅适用于主要导航链接块; 通常,<footer>元素通常包含一个链接列表,这些链接不需要出现在<footer>元素中。 - 
一个文档可能包含多个
<nav>元素,例如,一个用于网站导航,一个用于页内导航。 - 
用户代理,例如针对残障用户的屏幕阅读器,可以使用这个元素来决定是否跳过导航内容的初始渲染。
 
例子
例1
这个例子中, <nav> 用于包含一个无序的链接列表 (<ul>)。配合适当的 CSS, 可以将它改为边栏、导航栏或下拉菜单。
<!DOCTYPE html><html><head>  <meta http-equiv="content-type" content="text/html; charset=utf-8" />  <title>nav exmaple</title>  <style type="text/css">    html {background-color: white; }  </style></head><body><nav class="menu">  <ul>    <li><a href="#">Home</a></li>    <li><a href="#">About</a></li>    <li><a href="#">Contact</a></li>  </ul></nav></body></html>
例2
nav 元素的语义是提供链接。然而,nav 元素不是必须包含列表,它也可以包含其他类型的内容。在这个导航块中,链接是以散文形式提供的:
<!DOCTYPE html><html><head>  <meta http-equiv="content-type" content="text/html; charset=utf-8" />  <title>nav exmaple</title>  <style type="text/css">    html {background-color: white; }  </style></head><body><nav>  <h2>Navigation</h2>  <p>    You are on my home page. To the north lies <a href="/blog">my blog</a>, from    whence the sounds of battle can be heard. To the east you can see a large    mountain, upon which many <a href="/school">school papers</a> are littered.    Far up this mountain you can spy a little figure who appears to be me,    desperately scribbling a <a href="/school/thesis">thesis</a>.  </p>  <p>    To the west are several exits. One fun-looking exit is labeled    <a href="https://games.example.com/">"games"</a>. Another more    boring-looking exit is labeled <a href="https://isp.example.net/">ISP™</a>.  </p>  <p>    To the south lies a dark and dank <a href="/about">contacts page</a>.    Cobwebs cover its disused entrance, and at one point you see a rat run    quickly out of the page.  </p></nav></body></html>