jquery - 如何使用 keyup 计算 onchange

Question

我有 3 个输入。套餐 - 总计 - 价格

如何让套餐改变时价格也跟着改变。

$('#the_total').keyup(function () {
    var the_total = $("#the_total").val();
    var get_package = $("#package").val();
    if (get_package == 'Package A') {
        var total = the_total * 100;
    } else {
        var total = the_total * 200;
    }
    $("#price").val(total);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<select id="package">
    <option value="Package A">Package A</option>
    <option value="Package B">Package B</option>
</select>
<input type="text" id="the_total" name="total">
<input type="text" id="price" name="price">

Answer 1

在更改事件时触发 keyup。

$('#the_total').keyup(function() {
  var the_total = $("#the_total").val();
  var get_package = $("#package").val();
  if (get_package == 'Package A') {
    var total = the_total * 100;
  } else {
    var total = the_total * 200;
  }
  $("#price").val(total);
});

$('#package').change(function() { // on change
  $('#the_total').keyup(); // trigger this
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<select id="package">
  <option value="Package A">Package A</option>
  <option value="Package B">Package B</option>
</select>

<input type="text" id="the_total" name="total">
<input type="text" id="price" name="price">