javascript - 设置下拉菜单的选定值

Question

下面的代码只能运行 1 次，而不是每次

 var selectedVal = $('#drpGender_0').find("option:selected").text();

    if (selectedVal == "Male") {
        $('#drpGender_1').find("option:contains('Male')").text('Male').attr("selected", false);
        $('#drpGender_1').find("option:contains('Female')").text('Female').attr("selected", "selected");
    }
    else if (selectedVal == "Female") {

        $('#drpGender_1').find("option:contains('Female')").text('Female').attr("selected", false);
        $('#drpGender_1').find("option:contains('Male')").text('Male').attr("selected", "selected");

    }
};

提前致谢

Answer 1

$('#drpGender_0').on('change', function() {
  var selectedVal = $('#drpGender_0').val();

  if (selectedVal == "Male") {
    $('#drpGender_1').val('Female');
  } else if (selectedVal == "Female") {
    $('#drpGender_1').val('Male');
  }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<select id="drpGender_0">
  <option value="">Select Gender</option>
  <option value="Male">Male</option>
  <option value="Female">Female</option>
</select>

<select id="drpGender_1">
  <option value="">Select Gender</option>
  <option value="Male">Male</option>
  <option value="Female">Female</option>
</select>

您还可以使用代码

$('#drpGender_0').on('change', function() {
  var selectedVal = $('#drpGender_0').val();

  if (selectedVal == "Male") {
    $('#drpGender_1').find("option:contains('Female')").attr("selected", "selected");

  } else if (selectedVal == "Female") {
    $('#drpGender_1').find("option:contains('Male')").attr("selected", "selected");
  }
});