<html>
<body>
<ol id="myOl" start="50">
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ol>
<p>点击按钮返回有序列表的 start 属性的值。</p>
<p id="demo"></p>
<button onclick="myFunction()">尝试一下</button>
<script>
function myFunction()
{
var x = document.getElementById("myOl").start;
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>