摆放在哪里都行,head,body,html外都行,但是规范是摆放在head中
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="index.js"></script>
</head>
<body>
<script type="text/javascript">
alert("小试牛刀");
</script>
</body>
</html>
<script type="text/javascript">
alert("大试牛刀");
</script>
JS可以直接在HTML中写,也可以写一个JS文件,然后引入HTML
<script type="text/javascript" src="index.js"></script>
