Re: Re: Credit card checks?

There is a credit card validating class on phpclasses.org under e-commerce. "Martin Towell" <martin.towell@world.net> wrote in message news:6416776FCC55D511BC4E0090274EFEF5034CFBAF@EXCHANGE... > Try this: > > function do_mod_10($num) > { > // The Luhn formula works right to left, so reverse the number. > $num = strrev($num); > $total = 0; > for ($i = 0, $j = 1; $i < strlen($num); $i++, $j=3-$j) > { > $digit = $num[$i] * $j; > if ($digit > 9) $digit -= 9; > $total += $digit; > } > > return ($total % 10 == 0); > } > > -----Original Message----- > From: Mark McCulligh [mailto:mmcculli@sykescanada.com] > Sent: Wednesday, July 24, 2002 10:47 AM > To: php-general@lists.php.net > Subject: [PHP] Re: Credit card checks? > > > You could use an algorithms called mod10. Both Visa, MasterCard and I think > most other credit cards use the mod10 algorithm. A credit card must pass a > mod10 test to be a valid number(Like a Regular Expression test). It won't > tell you if the number exist, but it will tell you if it could exist. I > also know the mod10 is used for Canadian Social Security numbers (SIN). > > Unfortunately I have never seen a PHP function for it, I only used mod10 in > a language called Uniface by Compuware. I know there is another name for > it also, but I can't remember it right now. > > It is a great test, someone just typing in numbers at random will have a > terrible time guessing a number right. I have never seen someone do it let. > Then you can use the first character of the number to test the card type. > > I will see if I can locate the algorithm and email it too you. > > > Mark > > "Jas" <jlgerfen@hotmail.com> wrote in message > news:20020723181239.25134.qmail@pb1.pair.com... > > Just wondering if anyone has come across the need to develop a class to > test > > a string of numbers based on a credit card type. If you have where would > I > > be able to get information on what string of numbers is consistent with > each > > of the different credit cards? Any help would be appreciated! > > Jas > > > > > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php