ImplementationOfLuhnAlgorithm.js

// Write a JavaScript program to implement the Luhn Algorithm used to validate identification numbers. For example, credit card numbers, IMEI numbers, National Provider Identifier numbers etc.

const luhnCheck = (num) => {
  let arr = (num + "")
    .split("")
    .reverse()
    .map((x) => parseInt(x));

  let lastDigit = arr.splice(0, 1)[0];
  let sum = arr.reduce(
    (acc, val, i) => (i % 2 !== 0 ? acc + val : acc + ((val * 2) % 9) || 9),
    0
  );
  sum += lastDigit;

  return sum % 10 === 0;
};

console.log(luhnCheck("4485275742308327"));
console.log(luhnCheck(6011329933655299));