Luhn Algorithm

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

Swift port can be found at https://github.com/MaxKramer/SwiftLuhn.

It's as simple as calling one single method; no special formatting is required.

You must run pod install before opening the Example Project's '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

Name	Website	Reason
Paypal	http://www.paypalobjects.com/en_US/vhelp/paypalmanager_help/credit_card_numbers.htm	List of valid credit card numbers for the unit tests

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.