Heyo！我正在使用随机数生成器来选择图标。然后我将它设置为setAttribute（）。试图设置它不起作用。我做错了什么？
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
var number = Math.floor((Math.random() * 5) + 1);
var ico = number + ".ico"
setAttribute(href, ico);
</script>
<title>Cool Server People!</title>
<link rel="stylesheet" href="style.css">
<link rel="shortcut icon" href= "1.ico"/>
</head>
<body>
<div class="header">
<h1>Cool Server People</h1>
</div>
<div class="space">
</div>
<div class="blog">
<a href="test-post.html" class="post">Blog Post</a>
<p>asdfdasdfasdfasdfa</p>
</div>