Question

你好，我需要帮助这个代码，它总是进入其他条件如果值和文本匹配，我想从下拉列表中抄送文本，然后我想隐藏一些div：

jQuery("#myid").on('change', function () {
    if(jQuery('#myid').val() == 'Well, this is a dummy text') {
        alert(" hello");
    } else {
        alert("World");
    }
});



<select name="testtype" id="myid" class="validate[required]" style="font-size:12px; font-family:arial">
                <option selected="selected" value="">-- Make your selection --</option>
                <option id="first" value="Health, Safety and Environment Test for Operatives ">Health, Safety and Environment Test for Operatives </option>
                <option value="Supervisory-English only">Supervisory-English only</option>
                <option value="Health, Safety and Environment Test for Managers and Professionals -English only">Health, Safety and Environment Test for Managers and Professionals -English only</option>
                <option value="Demolition-English only">Demolition-English only</option>
                <option value="Highway Works-English only">Highway Works-English only</option>
                <option value="Specialist Work at Hight-English only">Specialist Work at Hight-English only</option>
                <option value="Lifts and Escalators-English only">Lifts and Escalators-English only</option>
                <option value="Tunnelling-English only">Tunnelling-English only</option>
                <option value="Heating, Ventilation Air Conditioning and Refrigeration (HAVCR)-English only">Heating, Ventilation Air Conditioning and Refrigeration (HAVCR)-English only</option>
                <option value="Plumbing (JIB)-English only">Plumbing (JIB)-English only</option>
            </select>

Answer 1

我想从下拉列表中抄送文本

看起来您想要匹配所选选项的文本而不是值，那么您应该使用.text()而不是.val()来获取文本，这将返回值，选择器应该像：

jQuery('#myid option:selected').text()

代码：

＆＃13;

jQuery("#myid").on('change', function() {
  //if (jQuery('#myid option:selected').text() == ...){
  //Or
  if (jQuery(this).val() == 'Health, Safety and Environment Test for Operatives ') {
    alert(" hello");
  } else {
    alert("World");
  }
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<select name="testtype" id="myid" class="validate[required]" style="font-size:12px; font-family:arial">
  <option selected="selected" value="">-- Make your selection --</option>
  <option id="first" value="Health, Safety and Environment Test for Operatives ">Health, Safety and Environment Test for Operatives </option>
  <option value="Supervisory-English only">Supervisory-English only</option>
  <option value="Health, Safety and Environment Test for Managers and Professionals -English only">Health, Safety and Environment Test for Managers and Professionals -English only</option>
  <option value="Demolition-English only">Demolition-English only</option>
  <option value="Highway Works-English only">Highway Works-English only</option>
  <option value="Specialist Work at Hight-English only">Specialist Work at Hight-English only</option>
  <option value="Lifts and Escalators-English only">Lifts and Escalators-English only</option>
  <option value="Tunnelling-English only">Tunnelling-English only</option>
  <option value="Heating, Ventilation Air Conditioning and Refrigeration (HAVCR)-English only">Heating, Ventilation Air Conditioning and Refrigeration (HAVCR)-English only</option>
  <option value="Plumbing (JIB)-English only">Plumbing (JIB)-English only</option>
</select>

＆＃13;

Answer 2

错误是您已将选项的值分配给数字和＆amp;您正在与它进行比较，因此它在if语句中返回false。但

如果您与.text()进行比较，则会获得每个选项的所有文字这就是为什么它在if语句
中失败的原因

＆＃13;

$("#myid").change(function(){

  if( $(this).val()=='Well,this is a dummy text' ) {
    alert('hello');
  }
  else
    alert("wolrd");
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<select id="myid">
<option value="1">wolrd</option>
<option value="2">hello</option>
<option value="Well,this is a dummy text">Well,this is a dummy text</option>

</select>

＆＃13;

IF语句不适用于jquery

2 个答案: