$('select').change(function but only on a specific dropdown? (HTML, Javascript)

Question

我正在尝试使用此代码：

$(document).ready(function () {
$('select').change(function () {
    alert(this.value);
});

Alerts a message but only when one of the various dropdowns onscreen is selected.但只要我选择任何下拉菜单，它就会起作用。我怎样才能让它只适用于一个特定的下拉菜单？

Answer 1

只需给您各自的 select 标签一个 ID，然后将该 ID 用于您的 select 或 jQuery:

$('#select1').change(function () 
{
    alert(this.value);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<select id="select1">
  <option value="">--Please Choose--</option>
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

<select id="select2">
  <option value="">--Please Choose--</option>
  <option value="A">Apple</option>
  <option value="B">Banana</option>
  <option value="C">Cherry</option>
</select>

$('select').change(function but only on a specific dropdown? (HTML, Javascript)

$('select').change(function but on only one specific dropdown? (HTML, Javascript)

javascript

html

dropdown