​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript 变量</h1>
​
<p>相加 5 + 2 + 3 的结果：</p>
​
<p id="demo"></p>
​
<script>
var x = 3 + 5 + 8;
document.getElementById("demo").innerHTML = x;
</script>
​
</body>
</html>
​