html==========
<body>
<div id="div1">12312312123121231212312<br>1231212<br>31212312123121<br><br>2312123121231<br><br><br>21231212<br><br>312123<br><br>1212312123121231212312123<br><br><br><br></div>
<br><br><br><br><br><br>
<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
</body>
css================
#div1{overflow:scroll;width: 100px;height: 100px;border: 1px solid #000;}
js======================
var div=document.getElementById('div1');
alert(div.clientHeight); //86
alert(div.scrollHeight); //276
alert(document.body.clientHeight); //1390
alert(document.body.scrollHeight); //1410
为什么div.clientHeight和div.scrollHeight差这么多?
