js getBoundingClientRect

<div id="box"></div>
var object=document.getElementById('box'); 
rectObject = object.getBoundingClientRect();
 
    rectObject.top：元素上边到视窗上边的距离;
    rectObject.right：元素右边到视窗左边的距离;
    rectObject.bottom：元素下边到视窗上边的距离;
    rectObject.left：元素左边到视窗左边的距离;
    rectObject.width：是元素自身的宽
    rectObject.height是元素自身的高