![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Correction status：Uncorrected
Teacher's comments：
Collection
Collection
1、position: relative;相对位置进行移动；
2、用setInterval() 方法设置定时器，会不停地调用函数，直到 clearInterval() 被调用或窗口被关闭；
3、 ball.style.left = ball.style.top = count + 'px'; 来设置向左和上进行移动；
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<style>
div{
border: 2px solid #000;
height: 40px;
width: 40px;
border-radius: 40px;
margin: 50px 10px;
background-color: #000;
box-shadow: 2px 2px 2px #000;
position: relative;
}
</style>
<body>
<button type="button" onclick="myBall()">点击</button>
<div id="ball"></div>
<script>
function myBall() {
var ball = document.getElementById("ball");
var count = 0;
var id = setInterval(frame, 10);
function frame() {
if (count < 100) {
cont++;
ball.style.left = ball.style.top = count + 'px';
} else {
clearInterval(id);
}
}
}
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例