Selecting table columns (jQuery)

问题

I want to give ALL (including <th>) cells of FIRST and LAST columns some specific classes, I tried this:

$("table tr:first-child td:first-child").addClass("first-col-cell");
$("table tr:last-child td:last-child").addClass("last-col-cell");

..but it doesn't seem to work.

Would appreciate any help.

回答1:

EDIT: Your selector was pretty close:

<script type="text/javascript">
    $(function() {
        $("table tr td:first-child").text('hello');
        $("table tr td:last-child").text('goodbye');
    });
</script>

<table>
    <tr>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
    </tr>
</table>

回答2:

If th elements matter... not sure how you'd want to treat colspans either.

<!doctype html>
<table>
    <tr>
    <th></th>
    <td>blah</td>
        <td></td>
    </tr>
    <tr>
        <td colspan="2"></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
    <td>blah</td>
        <td></td>
    </tr>
    <tr>
        <td></td>
    <td>blah</td>
        <td></td>
    </tr>
</table>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script type="text/javascript">
    $(function() {
      $("table tr :first-child").text('first').css('background', 'yellow');
      $("table tr :last-child").text('last').css('background', 'brown');
    });
</script>

回答3:

Try breaking it down a little, the traversing you're doing is incorrect

// This will take the first child which is a TD, within any TR in the table.
$("table tr td:first-child").addClass("first-col-cell");

// This will take the first child which is a TR within the table.
$("table tr:first-child").addClass("first-col-cell");

// Just like the above, except now we're doing the last occurances
$("table tr td:last-child").addClass("last-col-cell");
$("table tr:last-child").addClass("last-col-cell");

Then we just need to make sure the mark up is all good

<table>
<tr>
    <td>1</td>
    <td>1</td>
    <td>1</td>
    <td>1</td>
</tr>
<tr>
    <td>2</td>
    <td>2</td>
    <td>2</td>
    <td>2</td>
</tr>
<tr>
    <td>3</td>
    <td>3</td>
    <td>3</td>
    <td>3</td>
</tr>

And then jQuery should go through each one with the following results

<table>
    <tr class="first-col-cell">
        <td class="first-col-cell">1</td>
        <td>1</td>
        <td>1</td>
        <td class="last-col-cell">1</td>
    </tr>
    <tr>
        <td class="first-col-cell">2</td>
        <td>2</td>
        <td>2</td>
        <td class="last-col-cell">2</td>
    </tr>
    <tr class="last-col-cell">
        <td class="first-col-cell">3</td>
        <td>3</td>
        <td>3</td>
        <td class="last-col-cell">3</td>
    </tr>
</table>

来源：https://stackoverflow.com/questions/1483996/selecting-table-columns-jquery

标签

jquery

select

html-table

cell