​x
 
<!DOCTYPE html>
<html>
<body>
​
<p>在输入字段中按键盘上的某个键。</p>
​
<input type="text" size="40" onkeydown="myFunction(event)">
​
<p id="demo"></p>
​
<script>
function myFunction(event) {
  var x = event.key;
  document.getElementById("demo").innerHTML = "The pressed key was: " + x;
}
</script>
​
</body>
</html>
​