<html>
<body>
<p>点击按钮创建一个 OL 元素和一个 LI 元素。</p>
<p id="demo"></p>
<button onclick="myFunction()">尝试一下</button>
<script>
function myFunction()
{
var x = document.createElement("OL");
x.setAttribute("id", "myOl");
document.body.appendChild(x);
var y = document.createElement("LI");
var t = document.createTextNode("Coffee");
y.appendChild(t);
document.getElementById("myOl").appendChild(y);
}
</script>
</body>
</html>