javascript - 使用javascript在表中创建值的总和

Question

想要替换所有的“？”在下表中包含预期值。

我应该只向 <th> 添加类吗？对它们有值(value)并添加它们？

<table id="repair-invoice">
    <tr>
        <th>Item</th>
        <th>Parts</th>
        <th>Labor</th>
        <th>Total</th>
    </tr>
    <tr>
        <td>Automatic Transmission Replacement</td>
        <td>$1,809.99</td>
        <td>$830.00</td>
        <td>?</td>
    </tr>
    <tr>
        <td>Exhaust system replace</td>
        <td>$279.99</td>
        <td>$225.00</td>
        <td>?</td>
    </tr>
    <tr>
        <td>Replace air filter</td>
        <td>$9.99</td>
        <td>$0.00</td>
        <td>?</td>
    </tr>
    <tr>
        <td colspan="3">Total</td>
        <td>?</td>
    </tr>
</table>

Answer 1

您可以遍历行/列组合和值的总和

var sum = 0;
$('#repair-invoice tr').slice(1, -1).each(function() {
  var $tr = $(this),
    total = 0;
  $tr.find('td').slice(1, -1).each(function() {
    total += +$(this).text().replace(/\$|,/g, '') || 0;
  });
  $tr.find('td:last-child').text(total);
  sum += total;
});
$('#repair-invoice tr:last-child td:last-child').text(sum.toFixed(2)); //will have to format and display the value

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="repair-invoice">
  <tr>
    <th>Item</th>
    <th>Parts</th>
    <th>Labor</th>
    <th>Total</th>
  </tr>
  <tr>
    <td>Automatic Transmission Replacement</td>
    <td>$1,809.99</td>
    <td>$830.00</td>
    <td>?</td>
  </tr>
  <tr>
    <td>Exhaust system replace</td>
    <td>$279.99</td>
    <td>$225.00</td>
    <td>?</td>
  </tr>
  <tr>
    <td>Replace air filter</td>
    <td>$9.99</td>
    <td>$0.00</td>
    <td>?</td>
  </tr>
  <tr>
    <td colspan="3">Total</td>
    <td>?</td>
  </tr>
</table>