如何根据从另一个下拉列表中选择的内容创建动态(更改)下拉列表

<select id="mainList" onchange="updateSubList()">
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<select id="subList">
  <!-- 这里的选项将根据主列表的选择动态生成 -->
</select>

function updateSubList() {
  var mainList = document.getElementById("mainList");
  var subList = document.getElementById("subList");
  var selectedOption = mainList.value;

  // 清空从属列表的选项
  subList.innerHTML = "";

  // 根据主列表的选择生成从属列表的选项
  if (selectedOption === "option1") {
    var option1 = document.createElement("option");
    option1.text = "选项1-1";
    subList.add(option1);

    var option2 = document.createElement("option");
    option2.text = "选项1-2";
    subList.add(option2);
  } else if (selectedOption === "option2") {
    var option3 = document.createElement("option");
    option3.text = "选项2-1";
    subList.add(option3);

    var option4 = document.createElement("option");
    option4.text = "选项2-2";
    subList.add(option4);
  } else if (selectedOption === "option3") {
    var option5 = document.createElement("option");
    option5.text = "选项3-1";
    subList.add(option5);

    var option6 = document.createElement("option");
    option6.text = "选项3-2";
    subList.add(option6);
  }
}

<select id="mainList" onchange="updateSubList()">
  <!-- 主列表的选项 -->
</select>

<select id="subList">
  <!-- 从属列表的选项将根据主列表的选择动态生成 -->
</select>