<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div{width: 10px;height: 10px;background-color: red;margin-top: 10px;position: absolute;}
</style>
<script>
window.onload = function(){
var divs = document.getElementsByTagName("div");
document.onmousemove = function(ev){
var e = ev || window.event;
divs[0].style.left = e.clientX + "px";
divs[0].style.top = e.clientY + "px";
for(var i = 0;i < divs.length; i--){
divs[i + 1].style.left = divs[i].offsetLeft + "px";
divs[i + 1].style.top = divs[i].offsetTop + "px";
}
}
}
</script>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</body>
</html>
这是我的代码，为什么divs[i + 1].style.left = divs[i].offsetLeft + "px";会报错？而下面这个就不会？
<script>
window.onload = function(){
var divs = document.getElementsByTagName("div");
document.onmousemove = function(ev){
var e = ev || window.event;
for(var i = divs.length - 1; i > 0; i--){
divs[i].style.left = divs[i - 1].offsetLeft + "px";
divs[i].style.top = divs[i - 1].offsetTop + "px";
}
divs[0].style.left = e.clientX + "px";
divs[0].style.top = e.clientY + "px";
}
}
</script>