Luhn Algorithm

This is just a quick port of the Luhn Algorithm, generally used for validating Credit Card details, to Objective-C (iOS).

I have included an example project showing how the class works. It's as simple as calling a single method. No special formatting required, it's all done within the class.

In order to use the example project, you must run pod install before opening the workspace.

Instructions

Import the header:

#import "Luhn.h"

Call the class method returning a BOOL as to whether the string is valid or not:

BOOL isValid = [Luhn validateString:@"some credit card number"];

if (isValid) {
    // process payment   
}
else {
    // alert user
}

Alternatively, you can use the NSString category (no additional imports required):

NSString *ccNumber = @"378282246310005";
BOOL isValid = [ccNumber isValidCreditCardNumber];

You can also get the type of the credit card i.e. Visa, Diners, Amex, etc:

OLCreditCardType cardType = [ccNumber creditCardType];
// or
OLCreditCardType cardType = [Luhn typeFromString:ccNumber];

If you come across any issues or have a feature request, please open an issue or find me on:

Twitter: @maxkramer

Website: http://maxkramer.co

Sources

Thanks

Ayaka Nonaka for updating the Cocoapod spec and helping me with other aspects of the project!

Twitter: @ayanonagon

License

This project is licensed under the MIT license.