从数组中选择选项中的HTML显示信息？

<select id="optionSelect"></select>

var selectElement = document.getElementById("optionSelect");
var options = ["选项1", "选项2", "选项3"];

for (var i = 0; i < options.length; i++) {
  var option = document.createElement("option");
  option.text = options[i];
  selectElement.add(option);
}

window.onload = function() {
  var selectElement = document.getElementById("optionSelect");
  var options = ["选项1", "选项2", "选项3"];

  for (var i = 0; i < options.length; i++) {
    var option = document.createElement("option");
    option.text = options[i];
    selectElement.add(option);
  }
};