如何从下拉菜单中显示所选元素

<select id="myDropdown">
  <option value="element1">元素1</option>
  <option value="element2">元素2</option>
  <option value="element3">元素3</option>
</select>

var dropdown = document.getElementById("myDropdown");
var selectedElement = dropdown.options[dropdown.selectedIndex].value;

document.getElementById("result").innerText = "你选择了：" + selectedElement;

<select id="myDropdown">
  <option value="element1">元素1</option>
  <option value="element2">元素2</option>
  <option value="element3">元素3</option>
</select>

<div id="result"></div>

<script>
  var dropdown = document.getElementById("myDropdown");
  dropdown.onchange = function() {
    var selectedElement = dropdown.options[dropdown.selectedIndex].value;
    document.getElementById("result").innerText = "你选择了：" + selectedElement;
  };
</script>