代码示例:(标识:hdom_select_options)
<!DOCTYPE html>
<html>
<head>
<script>
function getOptions() {
  var x = document.getElementById("mySelect");
  var txt = "";
  var i;
  for (i = 0; i < x.length; i++) {
    txt = txt + " " + x.options[i].text;
  }
  document.getElementById("demo").innerHTML = txt;
}
</script>
</head>
<body>

<form>
请选择您喜欢的水果:
<select id="mySelect">
  <option>Apple</option>
  <option>Orange</option>
  <option>Pineapple</option>
  <option>Banana</option>
</select>
<br><br>
<input type="button" onclick="getOptions()" value="输出所有选项">
</form>

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

</body>
</html>
运行结果: