​x
 
<!DOCTYPE html>
<html>
<body>
​
<p>y = 5，计算 x = y / 2，并显示 x：</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var y = 5;
  var x = y / 2;
  document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>
</html>
​