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问题:

i'm looking at the W3Schools demo of using the <COL> element to align columns:

<table width="100%" border="1">
  <col align="left" />
  <col align="left" />
  <col align="right" />
  <tr>
    <th>ISBN</th>
    <th>Title</th>
    <th>Price</th>
  </tr>
  <tr>
    <td>3476896</td>
    <td>My first HTML</td>
    <td>$53</td>
  </tr>
</table>

And browser's rendering of it is not encouraging:

Chrome (10.0.648.127):

FireFox (3.6.8):

Internet Explorer 9 (standards mode):

Internet Explorer 8 (standards mode):

Internet Explorer 7 (standards mode):

Internet Explorer (quirks mode):

It's interesting to note that <COL align> used to work in browsers, and the feature was taken away in ie8. (And Chrome, with position of being the arbiter of all things perfect, doesn't support it.)

This makes me wonder if <COL align> is something that's not supposed to work.

Has <COL align> been deprecated?

Update One

i understand that it hasn't been formally deprecated. But the fact that browsers used to support it, then stopped supporting it makes me believe that there is some historical story that i'm missing. i assume the intentional removal of col align support from IE, and the continued lack of support from other browsers, indicates something is going on.

Update Two

i was mistakenly assuming lack of support for all features of <COL> meant <COL> itself isn't supported. i mistakenly assumed that since the only attribute i was trying wasn't working: that the element wasn't working. This was my mistake; and in hindsight i should have asked if "COL align" is deprecated (which it is).

In my defense i assumed an example would have been shown what wasn't working "anymore".

回答1:

Yes, the align attribute of <col /> no longer appears in HTML5. Says the spec!

Also, it's worth noting that you can't achieve a similar result using CSS on the <col /> tag. The style attribute (or induced style from id, class, etc.) only takes into account properties that sensibly apply to the column itself. That is, while each <td /> can contain text content and thus can have attributes like text-align set, the <col /> element does not contain text and thus none of the text-level styles apply. (Block-level stuff like background-color still works.)

However, in basic cases not involving colspan or rowspan, you can select blocks of <td />s (and thus "columns" in a sense) by using the CSS pseudo-class :nth-of-type. E.g. to center the third column of the table with class c3 use

table.c3 td:nth-of-type(3) { text-align: center; }

Edit by OP:

From The HTML Standard:

15 Obsolete features
15.2 Non-conforming features

The following attributes are obsolete (though the elements are still part of the language), and must not be used by authors: ...
align on col elements
...

Use CSS instead.

The WHATWG wiki gives some recommended alternatives for various obsolete presentational attributes:

Attribute              CSS equivalent
=====================  =====================================
align on col elements  'text-align' on the appropriate td/th

回答2:

Try

<!doctype html>
<html>
  <head>
    <title>Table</title>
    <style>
      table.foo td:nth-of-type(2) {
        font-style: italic;
      }
    </style>
  </head>
  <body>
    <table class="foo">
      <thead>
        <tr> <th>first</th> <th>second</th> </tr>
      </thead>
      <tbody>
        <tr> <td>bar</td> <td>baz</td> </tr>
        <tr> <td>bim</td> <td>buh</td> </tr>
      </tbody>
    </table>
  </body>
<html>

Which renders as:

回答3:

[edit] Uggh, you changed your question to refer specifically to the align property.

No, it hasn't been deprecated. Browser support is there but the implementation and extent are varied. The only cross-browser success I've really had in using it has been with setting widths for entire columns.

Notes from W3:

Firefox, Chrome, and Safari only support the span and width attributes of the colgroup element.
Only the width attribute [of the col element] works in Firefox (none of the other attributes).

回答4:

The <col> tag is not deprecated.

See: How to use <col> tag correctly and is it supported in all browser? I think this answer clarifies its usage, and explains some of the trouble you are having with it.

It is part of XHTML and HTML 5. http://www.tutorialspoint.com/html5/html5_tags.htm

回答5:

No it has not, it is both part of the html4 spec and the html5 spec.

http://www.w3.org/TR/html401/struct/tables.html#h-11.2.4.2

http://dev.w3.org/html5/markup/col.html

http://www.html-5.com/tags/col-tag/

回答6:

In the interest of making the markup semantically meaningful have you considered substituting your <col> tags with <colgroup>?

<col> is purely used for styling whereas <colgroup> can be used to group related columns (Perhaps this is why you intend to align two of them left?) You can then apply CSS to the various colgroups to style them accordingly.