js为页面插入元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
#dv {
width: 600px;
height: 600px;
background-color: black;
border: 2px solid yellow;
}
span {
position: absolute;
color: yellow;
font-size: 30px;
}
</style>
</head>
<body>
<input type="button" id="start" value="闪起来">
<div id="dv"></div>
<script>
document.getElementById('start').addEventListener('click',function () {
setInterval(function () {
var x = parseInt(Math.random()*600);
var y = parseInt(Math.random()*600);
var dvObj = document.getElementById('dv');
dvObj.innerHTML = '<span>★</span>';
dvObj.firstElementChild.style.left = x+'px';
dvObj.firstElementChild.style.top = y+'px';
},10)
},false)
</script>
</body>
</html>