getElementsByTagName 返回数组

node2:/var/www/html/jquery#cat t13.html 
<p>测试1</p>
<p>测试2</p>
<script type="text/javascript" src="jquery-2.2.2.min.js"></script>
<script type="text/javascript" src="t13.js"></script>

var items = document.getElementsByTagName("p");  //获取网页中所有的p元素 


node2:/var/www/html/jquery#cat t13.js
var items = document.getElementsByTagName("p"); 
console.log(items);
console.log(items[0].innerHTML);
console.log(items[1].innerHTML);