abstract：<!DOCTYPE html><html> <head> <meta charset="UTF-8" /> <meta name="viewport" content="width=device-width, initial-scale=
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<link rel="stylesheet" type="text/css" href="font-awesome/css/font-awesome.css"/>
<script type="text/javascript" src="js/jquery-3.2.1.min.js"></script>
<title>作业</title>
<style type="text/css">
*{margin: 0;padding: 0;}
body{background-color: #ccc;;}
.head{height: 40px;width: 100%;background-color: red;position: fixed;;top: 0;}
#tips{position: fixed;bottom: 10px;right: 20px;}
#tips p{cursor: pointer;padding: 10px;margin-top: 5px;background-color: yellow;border-radius: 8px;color: #000;}
</style>
<script type="text/javascript">
$(function(){
$('#toUp').fadeOut(1000)
$(window).on('scroll',function(){ //或者 $(window).scroll(fnuction(){...})
var Hg=$(window).scrollTop();
if(Hg>50){
$('#toUp').fadeIn(1000)
}else{
$('#toUp').fadeOut(1000)
}
})
})
</script>
</head>
<body>
<div id="body">
<div></div>
<div id="tips">
<p><i class="fa fa-caret-square-o-up"></i></p>
<p><i class="fa fa-check-square"></i></p>
<p id="toUp"><i class="fa fa-hand-stop-o"></i></p>
</div>
</div>
<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br />
</body>
</html>
Correcting teacher：查无此人Correction time：2019-05-09 14:08:46
Teacher's summary：完成的不错。js和jq语句结束后，增加;号。继续加油。