滚动条相关

滚动条距离顶部的距离

let ele=document.getElementById("demo")
console.log(ele.scrollTop)

滚动条距离底部的距离

let ele=document.getElementById("demo")
console.log(ele.scrollHeight-ele.scrollTop-ele.clientHeight)

来源：https://www.cnblogs.com/huihuihero/p/11640966.html