This project checks if a card number is in a valid format for a Mastercard. Click the green flag and then enter the card number to check at the prompt. The cat will tell you the result.
The script does not store entered credit card details. The script runs checks that are in the public domain: a) Mastercard account ranges are: 510000 - 559999 and 222100 to 272099 b) The last digit (16th digit) is a check digit - the Luhn check digit. The script also checks c) That the entered card number is digits only d) That the entered card number is 16 characters long
