以上实例也可以这么写 - 在线编辑器

          <h1>我的网页</h1>
<p id="demo1"></p>
<p id="demo2"></p>
<script>
  a = 1;
  b = 2;
  c = a + b;
  document.getElementById("demo1").innerHTML = c;
  x = 1;
  y = 2;
  z = x + y;
  document.getElementById("demo2").innerHTML = z;
</script>
        