js使下拉框默认选中状态

<select id="mySelect">
  <option value="1">Option 1</option>
  <option value="2" selected>Option 2</option>
  <option value="3">Option 3</option>
</select>

<select id="mySelect">
  <option value="1">Option 1</option>
  <option value="2">Option 2</option>
  <option value="3">Option 3</option>
</select>

<script>
  document.addEventListener("DOMContentLoaded", function() {
    var selectElement = document.getElementById("mySelect");
    selectElement.value = "2"; // 设置默认选中值为"2"
  });
</script>

<select id="mySelect">
  <option value="1">Option 1</option>
  <option value="2">Option 2</option>
  <option value="3">Option 3</option>
</select>

<script>
  document.addEventListener("DOMContentLoaded", function() {
    var selectElement = document.getElementById("mySelect");
    var defaultValue = "2"; // 假设这是你的默认值
    selectElement.value = defaultValue;
  });
</script>