如何使用jquery更新表头

Question

我有一张桌子，我试图根据表格单元格中的值存在来创建这样的东西。

获得的结果 - jsFiddle Result

<table width="100%" border="1" cellspacing="0" cellpadding="0" class="top-table-bg" id="mytable">
                        <tbody><tr>
                            <th style="width:200px"><br>First Row<br>Second Row<br>Third Row<br>Forth Row<br></th>
                            <th style="width:200px"><p>Heading1<br>
                            </p>
                              <p>First Row<br>
                              </p></th>
                            <th style="width:200px"><p>Heading2
                              <br>
                          </p>
                              <p>Second Row
                                <br>
                          Forth Row<br>
                              </p></th>
                            <th style="width:200px"><p>Heading3
                              <br>
                          </p>
                              <p>Second Row<br>
                          Third Row<br>
                          <br>
                              </p></th>                         
                        </tr>
                        <tr>
                            <td style="width:200px;text-align:center;">First Row</td>
                            <td style="width:200px;text-align:center;">20</td>
                            <td style="width:200px;text-align:center;"></td>
                            <td style="width:200px;text-align:center;"></td>
                        </tr>
                        <tr>
                            <td style="width:200px;text-align:center;">Second Row</td>
                            <td style="width:200px;text-align:center;"></td>
                            <td style="width:200px;text-align:center;">20</td>
                            <td style="width:200px;text-align:center;">20</td>
                        </tr>
                        <tr>
                            <td style="width:200px;text-align:center;">Third Row</td>
                            <td style="width:200px;text-align:center;"></td>
                            <td style="width:200px;text-align:center;"></td>
                            <td style="width:200px;text-align:center;">20</td>
                        </tr>   
                        <tr>
                            <td style="width:200px;text-align:center;">Forth Row</td>
                            <td style="width:200px;text-align:center;"></td>
                            <td style="width:200px;text-align:center;">20</td>
                            <td style="width:200px;text-align:center;"></td>
                        </tr>       
                    </tbody></table>

这就是我尝试过的，但它填充了所有值:(

我的尝试 - jsFiddle Try

$('#mytable>tbody>tr').each( function(){
   if($(this).text() != '' ) {
   $('th').append($(this).children('td').first().text() + "<br>");
   }
});

让我知道我做错了什么..在jquery中开始......如果是一个基本的借口

Answer 1

$('#mytable > tbody > tr').each(function() {
  var $tr = $(this);

  $tr.children("td").not(":nth-child(1)").each(function() {
    if ($(this).text() != '') {
      var index = $(this).index() + 1;

      $("th")
        .filter(":nth-child(" + index + ")")
        .append("<br/>" + $tr.children("td:first").text());
    }
  });
})

#mytable th {
  width:200px;
}

#mytable td {
  text-align: center;
  width: 200px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table width="100%" border="1" cellspacing="0" cellpadding="0" class="top-table-bg" id="mytable">
  <tr>
    <th></th>
    <th>Heading1</th>
    <th>Heading2</th>
    <th>Heading3</th>
  </tr>
  <tr>
    <td>First Row</td>
    <td>20</td>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td>Second Row</td>
    <td></td>
    <td>20</td>
    <td>20</td>
  </tr>
  <tr>
    <td>Third Row</td>
    <td></td>
    <td></td>
    <td>20</td>
  </tr>
  <tr>
    <td>Forth Row</td>
    <td></td>
    <td>20</td>
    <td></td>
  </tr>
</table>

我还用外部CSS替换了内联样式声明。