如何从选项列表中选择值并将其字段显示在其他位置(例如在<input>中)

<select id="mySelect">
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

var selectElement = document.getElementById("mySelect");
var selectedValue = selectElement.value;

var inputElement = document.getElementById("myInput");
inputElement.value = selectedValue;

<select id="mySelect">
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<input id="myInput" type="text">

<script>
  var selectElement = document.getElementById("mySelect");
  var inputElement = document.getElementById("myInput");

  selectElement.addEventListener("change", function() {
    var selectedValue = selectElement.value;
    inputElement.value = selectedValue;
  });
</script>