Validate Credit Card (Luhn)

Validate a credit card number using the Luhn algorithm.

Code

General
const digits = cardNumber.replace(/\D/g, '').split('').map(Number);
const sum = digits.reverse().reduce((acc, d, i) => {
  if (i % 2) d *= 2;
  return acc + (d > 9 ? d - 9 : d);
}, 0);
return sum % 10 === 0;

Parameters

The credit card number to validate

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