在按钮上，单击在JavaScript中创建具有唯一id的动态下拉列表

<button id="btnCreateList">创建下拉列表</button>
<select id="dynamicList"></select>

var btnCreateList = document.getElementById("btnCreateList");
var dynamicList = document.getElementById("dynamicList");

btnCreateList.addEventListener("click", createDynamicList);

function createDynamicList() {
  // 清空下拉列表
  dynamicList.innerHTML = "";

  // 创建选项
  for (var i = 1; i <= 5; i++) {
    var option = document.createElement("option");
    var optionId = "option" + i;

    option.value = optionId;
    option.text = "选项 " + i;
    option.id = optionId;

    dynamicList.appendChild(option);
  }
}