Code snippet featuring 'col' and 'colspan' differs from general practice and from source of own example

[ghost]

Hi,

Re: the Example (rendered HTML table) and Code Snippet here https://www.w3.org/WAI/tutorials/tables/irregular/#table-with-two-tier-headers

The Example table (when you examine it) uses the following markup:

<colgroup>
<col>
</colgroup>
<colgroup span="2"></colgroup>
<colgroup span="2"></colgroup>

yet the Code Snippet provided uses this:

<col>
<colgroup span="2"></colgroup>
<colgroup span="2"></colgroup>

While both may be valid, I note that MDN introduce col by saying:

The HTML <col> element defines a column within a table and is used for defining common semantics on all common cells. It is generally found within a <colgroup> element.

Assuming MDN is correct, and col is generally found within a <colgroup> element, and given the actual table on the page follows that usage, I think it would be better if the Code Snippet were changed to match the HTML used by the table, i.e. with col inside a colgroup.

Thanks for these pages on tables, they are invaluable and visited by me repeatedly when coding complex tables. Brilliant!

Cheers,

Alan

[ghost]

Update: <colgroup> and <col> only needed for HTML 4?

I am attempting to find any reference to <colgroup> and <col> (elements, not attributes) being useful for anything other than perhaps styling (which we can do with CSS in the absence of these two). So far all I seem to find is related to HTML 4.01, not HTML 5.

If, as it seems, <colgroup> and <col> are only needed for HTML 4.01 and are redundant or at least of no help for a11y, in HTML5, it would be very helpful if this were noted.

[yatil]

You can see in the code that the raw HTML text has only <col> specified, the opening and closing <colgroup> tags are optional and hence not specified. In the DOM, they get added automatically.

I don’t think there is an HTML4/5 difference. Yes, colgroups and cols can be used for styling, but they also provide semantic grouping, that can affect header calculations.