​x
 
<!DOCTYPE html>
<html>
<body>
​
<select id="mySelect" autofocus>
  <option value="volvo">沃尔沃</option>
  <option value="saab">萨博</option>
  <option value="porsche">保时捷</option>
  <option value="audi">奥迪</option>
</select>
​
<p>单击按钮可查看下拉列表是否在页面加载时自动获得焦点。</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var x = document.getElementById("mySelect").autofocus;
  document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>
</html>
​