Implementation of the Luhn 10 algorithm to check validity of credit card numbers. See http://en.wikipedia.org/wiki/Luhn_algorithm for details on the algorithm.
var validCreditCard = function(a,b,c,d,e){for(d=+a[b=a.length-1],e=0;b--;)c=+a[b],d+=++e%2?2*c%10+(c>4):c;return!(d%10)};
validCreditCard('378282246310005'); //=> true
validCreditCard('378282246310006'); //=> false
// some numbers to test with
// 378282246310005 371449635398431 378734493671000
| // jquery invert plugin | |
| // by paul irish | |
| // some (bad) code from this css color inverter | |
| // http://plugins.jquery.com/project/invert-color | |
| // some better code via Opera to inverse images via canvas | |
| // http://dev.opera.com/articles/view/html-5-canvas-the-basics/#insertingimages | |
| // and some imagesLoaded stuff from me | |
| // http://gist.github.com/268257 |
| // See comments below. | |
| // This code sample and justification brought to you by | |
| // Isaac Z. Schlueter, aka isaacs | |
| // standard style | |
| var a = "ape", | |
| b = "bat", | |
| c = "cat", | |
| d = "dog", |