Abhishek Reddy — Sat, 07 Feb 2004 10:50:36 +0000

Hm, true, druagord. Guess I have to revisit my math.

I've used modulus in ASP to create evenly distributed results in three columns, similar to pagination. Very handy.

druagord — Fri, 06 Feb 2004 14:40:45 +0000

Another use of modulus i came across a few time is when displaying result in multiple pages. Let say i have 25 results per pages i do a query that comes up with 134 results i do
number of pages = ceil(134/25) = 6
number of result on the last page = 134%25 = 9

Suzanne — Fri, 06 Feb 2004 14:29:46 +0000

druagord wrote: 15%10 would be 5

http://www.google.com/search?q=15%2510

Google is so handy! Don't mind me while I walk through this for my own edification:

10 gahzinta* 15 once, remainder 5
2 gahzinta 3 once, remainder 1
8 gahzinta 16 twice, remainder 0
2 gahzinta $anyevennumber exactly, remainder 0

So if it's even, it returns 0, no matter what.

Excellent.

Now, how you do you set it up? Oh, of course, since two goes into any even number perfectly, you'll always get a remainder of zero for %2 if the number is even.

Nifty!

These are all zero:
http://www.google.com/search?q=36895825420%252
http://www.google.com/search?q=2%252
http://www.google.com/search?q=18%252

*gahzinta = "goes into" slang slang slang

Suzanne — Fri, 06 Feb 2004 14:19:02 +0000

Abhishek Reddy wrote: Suzanne, modulus is the standard way of colouring tables, afaik. What have you been using, then?

I don't colour table rows, as a habit. I haven't done anything (yet) that would require it (in php).

druagord — Fri, 06 Feb 2004 14:15:57 +0000

Quote:
2) your result would be 0.5

no 3/2 would give 1 reminder 1 so 3%2 would give 1 as a result. there are no decimals with modolus only integers. Try to remember the first division you made in school before you learned about decimals
15%10 would be 5

Abhishek Reddy — Fri, 06 Feb 2004 00:50:19 +0000

"modulus" means "remainder of". If you have 4%2 or mod (4, 2) your result will be 0. That is, 4 divided by 2 is 2, with 0 remaining. Whereas if you had 3%2 or mod (3, 2) your result would be 0.5, since 3 divided by 2 is 1 plus a remainder of 0.5. So you can test for even numbers by looking for a returned value of 0 after using %2. Anything else should be odd.

Suzanne, modulus is the standard way of colouring tables, afaik. What have you been using, then?

brady.k — Fri, 06 Feb 2004 00:40:45 +0000

I checked php.net for modulus, but it didn't help define it. What exactly is "modulus"?

Suzanne — Thu, 05 Feb 2004 18:01:43 +0000

No shame in being eager, heh. I thought to myself when you wrote that, well, hmmm, maybe I should post the whole function instead of just linking to it. Always thinking of the lurkers, that's me!

druagord — Thu, 05 Feb 2004 17:59:13 +0000

Quote:
That's what this guy has built his function around. I haven't had the need, but now that I know how, I'm thinking this would be interesting for colouring table rows?

it can be usefull for all kind of thing but your right thats how i use this most of the time. Sorry i didn't follow the link you put guess i was to eager to answer

Suzanne — Thu, 05 Feb 2004 17:53:57 +0000

That's what this guy has built his function around. I haven't had the need, but now that I know how, I'm thinking this would be interesting for colouring table rows?

<?php
// function: Check if a value ($value) is even or odd.

function even($value) {
        if (is_int($value)) {              // Per definition only integers can be odd/even
                if (($value % 2) == 0)) {  // Divide by 2 and if modulus is 0 we are even
                        return 1;          // Number is even
                } else {
                        return 0;          // Number is odd
                }
        } else {
                return 0;                  // Number is not an integer
        }
}
?>

from: Carl Swart