<body>
<div id="div" style="height:200px;width:200px;border:solid 50px red;overflow:auto;padding:50px;">
<div id="info" style="height:400px;width:400px;border:solid 1px blue;"></div>
</div>
<script>
var div = document.getElementById("div");
var hc = div.clientHeight; // 可视内容高度为283像素
var ho = div.offsetHeight; // 占据页面总高度为400像素
var hs = div.scrollHeight; // 展开滚动内容总高度为502像素
console.log(hc, ho, hs, 'fff') // 283 400 502 "fff"
</script>
</body>