scrollHeight

window.innerWidth

winWidth

function getInfo() 
{ 
var s = ""; 
s += " 网页可见区域宽："+ document.body.clientWidth; 
s += " 网页可见区域高："+ document.body.clientHeight; //body
s += " 网页可见区域宽："+ document.body.offsetWidth + " (包括边线和滚动条的宽)"; 
s += " 网页可见区域高："+ document.body.offsetHeight + " (包括边线的宽)"; 
s += " 网页正文全文宽："+ document.body.scrollWidth; 
s += " 网页正文全文高："+ document.body.scrollHeight; //窗口
s += " 网页被卷去的高(ff)："+ document.body.scrollTop; 
s += " 网页被卷去的高(ie)："+ document.documentElement.scrollTop; 
s += " 网页被卷去的左："+ document.body.scrollLeft; 
s += " 网页正文部分上："+ window.screenTop; 
s += " 网页正文部分左："+ window.screenLeft; 
s += " 屏幕分辨率的高："+ window.screen.height; 
s += " 屏幕分辨率的宽："+ window.screen.width; 
s += " 屏幕可用工作区高度："+ window.screen.availHeight; 
s += " 屏幕可用工作区宽度："+ window.screen.availWidth; 
s += " 你的屏幕设置是 "+ window.screen.colorDepth +" 位彩色"; 
s += " 你的屏幕设置 "+ window.screen.deviceXDPI +" 像素/英寸"; 
//alert (s); 
} 
getInfo(); 
<script type="text/javascript">
var a=0;
setInterval(function(){
    a= document.body.scrollHeight  
       console.log(a);
},400)

</script>