Credit Card Validator

A Credit Card Validator is a digital tool that checks the validity of a credit card number using a specific algorithm called the Luhn Algorithm. This algorithm is used to verify the integrity of credit card numbers and help prevent errors and fraud.

1. Card Number Input: You input the credit card number to be validated.
2. Luhn Algorithm:
   • Double-Digit Sum: Starting from the rightmost digit, double every other digit. If the doubled digit exceeds 9, add the digits together.
   • Sum Calculation: Add up all the digits, including the doubled digits.
   • Modulus 10 Check: If the sum is divisible by 10, the credit card number is considered valid.

Consider the credit card number 49927398716.

1. Double-Digit Sum:
   • 6 * 2 = 12 → 1 + 2 = 3
   • 1 * 2 = 2
   • 7 * 2 = 14 → 1 + 4 = 5
   • 9 * 2 = 18 → 1 + 8 = 9
   • 3 * 2 = 6
   • 7 * 2 = 14 → 1 + 4 = 5
   • 2 * 2 = 4
   • 9 * 2 = 18 → 1 + 8 = 9
   • 4 * 2 = 8
2. Sum Calculation: 3 + 2 + 5 + 9 + 6 + 5 + 4 + 9 + 8 = 51
3. Modulus 10 Check: 51 is not divisible by 10, so the credit card number is invalid.

Credit Card Validators are used to:

• Prevent Fraud: By verifying the validity of credit card numbers, they help reduce fraudulent transactions.
• Improve Data Quality: Ensuring that credit card information is accurate and error-free.
• Enhance Security: Protecting sensitive financial information.