getElementById ,getElementsByTagName
node2:/var/www/html#cat m28.html
<title></title>
<h3>例子</h3>
<p title="选择你最喜欢的水果.">你最喜欢的水果是?</p>
<ul>
<li id='aaa'>苹果</li>
<li>橘子</li>
<li>菠萝</li>
</ul>
<script>
var domObj = document.getElementById("aaa"); //获得DOM对象
console.log(domObj.innerHTML)
</script>
<title></title>
<h3>例子</h3>
<p title="选择你最喜欢的水果.">你最喜欢的水果是?</p>
<ul>
<li id='aaa'>苹果</li>
<li>橘子</li>
<li>菠萝</li>
</ul>
<script>
var domObj = document.getElementById("aaa"); //获得DOM对象
console.log(domObj.innerHTML)
var b=document.getElementsByTagName("li")
console.log(b[1].innerHTML)
</script>