在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
  $("input").keyup(function(event){ 
    $("div").html("Key: " + event.which);
  });
});
</script>
</head>
<body>

Enter your name: <input type="text">
<p>When you type in the field above, the div below will display the key number.</p>
<div />

</body>
</html>

源代码

动行结果