代码示例:(标识:jsck_node_lastchild_2)
<!DOCTYPE html>
<html>
<body>

<h1>Element 对象</h1>

<h2>lastChild 属性</h2>

<p>点击按钮可获取 select 元素最后一个子节点的文本。</p>

<select id="mySelect" size="5"><option>Audi</option><option>BMW</option><option>Saab</option><option>Volvo</option></select><br><br>

<button onclick="myFunction()">试一试</button>

<p id="demo"></p>

<script>
function myFunction() {
  let text = document.getElementById("mySelect").lastChild.text;
  document.getElementById("demo").innerHTML = text;
}
</script>

</body>
</html>
运行结果: