How to Alternate Table Row Colors in CSS and HTML

http://www.somacon.com/p338.php
How to Alternate Table Row Colors in CSS and HTML

I just completed this article. Comments welcome!

Re: How to Alternate Table Row Colors in CSS and HTML

John Smith wrote:
> http://www.somacon.com/p338.php
> How to Alternate Table Row Colors in CSS and HTML
>
> I just completed this article. Comments welcome!

Ok, that's a good explanation.

But you get 10 points off for that terrible aqua background color of
the page.

Oh wait, that's my default background color; you didn't specify one!

--
-bts
-This space intentionally left blank.

Re: How to Alternate Table Row Colors in CSS and HTML

Gazing into my crystal ball I observed John Smith
writing in news:W8udnajJNKhJIWvfRVn-2Q@comcast.com:

> http://www.somacon.com/p338.php
> How to Alternate Table Row Colors in CSS and HTML
>
> I just completed this article. Comments welcome!

For the ASP, this is a little cleaner, no need for confusing
response.writes:

Re: How to Alternate Table Row Colors in CSS and HTML

Adrienne wrote:
> Gazing into my crystal ball I observed John Smith
> writing in news:W8udnajJNKhJIWvfRVn-2Q@comcast.com:
>
>
>>http://www.somacon.com/p338.php
>>How to Alternate Table Row Colors in CSS and HTML
>>
>>I just completed this article. Comments welcome!
>
>
> For the ASP, this is a little cleaner, no need for confusing
> response.writes:
>
>

Re: How to Alternate Table Row Colors in CSS and HTML

> no need for confusing response.writes:

You've never had to performance tune an ASP site, have you ?

Re: How to Alternate Table Row Colors in CSS and HTML

On Mon, 08 Aug 2005 10:44:03 -0400, John Smith
wrote:

>Furthermore, if you use "mod" instead of "and", you are doing the
>equivalent of a division operation on every loop iteration.

Do you have a hat ? Because if you do, and this makes the slightest
difference, then I'll eat it.

>"Mod" takes dozens of CPU cycles whereas "and" typically takes only one.

Agreed. But it's the 21st century - we have CPU cycles to burn! In
amongst all the many tasks going on to output a page, I will be _amazed_
if the overhead due to mod vs. and (which I'm sure is real) is anything
like significant.

Personally I'd stick with Mod, not And. This is for three reasons:

- It's clearer. Code that's self-explanatory always beats code that
needs a comment to explain it.

- Code with Mod is easily changed to put the stripes out every 3 or 5
lines. And isn't.

- And relies on "And" meaning a bitwise and on that platform, not a
logical and. That's a big assumption to make for long-term code that
might get ported.

Re: How to Alternate Table Row Colors in CSS and HTML

Andy Dingley wrote:
> On Mon, 08 Aug 2005 10:44:03 -0400, John Smith
> wrote:
>
>
>>Furthermore, if you use "mod" instead of "and", you are doing the
>>equivalent of a division operation on every loop iteration.
>
>
> Do you have a hat ? Because if you do, and this makes the slightest
> difference, then I'll eat it.
>
>
>>"Mod" takes dozens of CPU cycles whereas "and" typically takes only one.
>
>
> Agreed. But it's the 21st century - we have CPU cycles to burn! In
> amongst all the many tasks going on to output a page, I will be _amazed_
> if the overhead due to mod vs. and (which I'm sure is real) is anything
> like significant.
>
> Personally I'd stick with Mod, not And. This is for three reasons:
>
> - It's clearer. Code that's self-explanatory always beats code that
> needs a comment to explain it.
>
> - Code with Mod is easily changed to put the stripes out every 3 or 5
> lines. And isn't.
>
> - And relies on "And" meaning a bitwise and on that platform, not a
> logical and. That's a big assumption to make for long-term code that
> might get ported.


<%
' http://www.arcticlabs.com/
Set objStopwatch = Server.CreateObject("Toolsack.Stopwatch")
objStopwatch.Start()
i = 0
For i = 0 To 1000000
'j = i Mod 2
j = i And 1
Next
Response.write FormatNumber(objStopwatch.Stop() * 1000, 10) & "
milliseconds"
%>

I did a little test to compare "Mod" vs "And", and I found no difference
in execution time for one million executions. The above script takes
about 915 ms on my system regardless of which line is uncommented. This
may mean the overhead of processing the individual line of script is
much higher than the difference in cost between the two operators.

Sometimes when one agressively tries to optimize code, one makes changes
that should work theoretically, but practically have no effect. I based
my experience with optimizing some C programs, where "mod" had a big
effect in some tight loops versus using "and".

In ASP, of your three reasons, I think number two is most compelling.

Re: How to Alternate Table Row Colors in CSS and HTML

Gazing into my crystal ball I observed dingbat@codesmiths.com writing in
news:1123512657.044175.32080@g47g2000cwa.googlegroups.com:

>> no need for confusing response.writes:
>
> You've never had to performance tune an ASP site, have you ?
>
>

Yes, I have, and I find that interleaved text output is
A) Faster
B) Easier to debug

Consider the following:

<% option explicit

dim i

response.write "

Re: How to Alternate Table Row Colors in CSS and HTML

Then your benchmarks need work.

ASP code _sucks_. The vast body of ASP code out there is hideous crap
produced by barely skilled HTML coders who suddenly decided (or were
told) that they were "programmers". Apart from the whole discipline of
decades of software engineering, they could benefit a lot by looking at
the Java world. In particular the emerging split between Servlets, JSP
and the Triangle pattern. There's a whole lot wrong with this
interleaved code and data approach when you have to manage major
branches in program execution.

Re: How to Alternate Table Row Colors in CSS and HTML

That's exactly my point. In a "bare code" benchmark, Mod may indeed
have some huge speed advantage over And.

But we're not coding benchmarks here, we're coding HTML output. In a
page that has database access and Server.HTMLEncode() in it, I'm just
not going to start worrying about the cost of doing Mod vs. And.

You'd be better off replacing the class selection for a selection
i.e.:
Response.Write ("");

by
Response.Write ((iRowCount++ %2) ? "" : " class='odd'>" ));

and saving yourself some string concatenation than you would by
counting the gnat's whiskers on this Mod