javascript - How do I auto-sum two boxes into a different box?

Question

I have two boxes, one named AuthorizedAmount and another named LessLaborToDate:

<div class="col-md-6">
  <div class="form-group">
    <label>Authorized Amount</label>
    <div class="input-group">
      <span class="input-group-addon">$</span>
      <input type="number" class="form-control" name="AuthorizedAmount" min=0 step="0.01" required>
    </div>
  </div>
</div>
<div class="col-md-6">
  <div class="form-group">
    <label>Less Labor to Date</label>
    <div class="input-group">
      <span class="input-group-addon">$</span>
      <input type="number" class="form-control" name="LessLaborToDate" min=0 step="0.01" required>
    </div>
  </div>
</div>

How do I get these two values automatically summed in another box, named Subtotal?

<div class="col-md-6">
  <div class="form-group">
    <label>Subtotal</label>
    <div class="input-group">
      <span class="input-group-addon">$</span>
      <input type="number" class="form-control" name="Subtotal" placeholder="Authorized Amount minus Less Labor to Date" min=0 step="0.01" readonly>
    </div>
  </div>
</div>

标签： javascriptjqueryhtmlasp.net-mvcrazor

Answer 1

使用 jquery，如下所示：

$("input[name='AuthorizedAmount'], input[name='LessLaborToDate']").change(function() {
    var sum = $("input[name='AuthorizedAmount']").val() + $("input[name='LessLaborToDate']").val();
    $("input[name='Subtotal']").val(sum);
});

您可能需要添加一些空检查，parseInt但您明白我希望的想法