Codecademy export

main.js

// All valid credit card numbers
const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8];
const valid2 = [5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9];
const valid3 = [3, 7, 1, 6, 1, 2, 0, 1, 9, 9, 8, 5, 2, 3, 6];
const valid4 = [6, 0, 1, 1, 1, 4, 4, 3, 4, 0, 6, 8, 2, 9, 0, 5];
const valid5 = [4, 5, 3, 9, 4, 0, 4, 9, 6, 7, 8, 6, 9, 6, 6, 6];

// All invalid credit card numbers
const invalid1 = [4, 5, 3, 2, 7, 7, 8, 7, 7, 1, 0, 9, 1, 7, 9, 5];
const invalid2 = [5, 7, 9, 5, 5, 9, 3, 3, 9, 2, 1, 3, 4, 6, 4, 3];
const invalid3 = [3, 7, 5, 7, 9, 6, 0, 8, 4, 4, 5, 9, 9, 1, 4];
const invalid4 = [6, 0, 1, 1, 1, 2, 7, 9, 6, 1, 7, 7, 7, 9, 3, 5];
const invalid5 = [5, 3, 8, 2, 0, 1, 9, 7, 7, 2, 8, 8, 3, 8, 5, 4];

// Can be either valid or invalid
const mystery1 = [3, 4, 4, 8, 0, 1, 9, 6, 8, 3, 0, 5, 4, 1, 4];
const mystery2 = [5, 4, 6, 6, 1, 0, 0, 8, 6, 1, 6, 2, 0, 2, 3, 9];
const mystery3 = [6, 0, 1, 1, 3, 7, 7, 0, 2, 0, 9, 6, 2, 6, 5, 6, 2, 0, 3];
const mystery4 = [4, 9, 2, 9, 8, 7, 7, 1, 6, 9, 2, 1, 7, 0, 9, 3];
const mystery5 = [4, 9, 1, 3, 5, 4, 0, 4, 6, 3, 0, 7, 2, 5, 2, 3];

// An array of all the arrays above
const batch = [
  valid1,
  valid2,
  valid3,
  valid4,
  valid5,
  invalid1,
  invalid2,
  invalid3,
  invalid4,
  invalid5,
  mystery1,
  mystery2,
  mystery3,
  mystery4,
  mystery5,
];

// Add your functions below:
const validateCred = (array) => {
  let runningTotal = 0;

  let counter = 0;
  for (let i = array.length - 1; i >= 0; i--) {
    counter++;
    let num = array[i];
    if (counter % 2 === 0) {
      num = num * 2;
      if (num > 9) {
        num = num - 9;
      }
    }
    runningTotal += num;
  }

  if (runningTotal % 10 === 0) {
    return "valid";
  } else {
    return "invalid";
  }
};

const findInvalidCards = (cardArray) => {
  const invalidCards = [];
  for (let i = 0; i < cardArray.length; i++) {
    const card = cardArray[i];
    if (validateCred(card) === "invalid") {
      invalidCards.push(card);
    }
  }
  return invalidCards;
};

const idInvalidCardCompanies = (invalidCardsArray) => {
  const companies = [];
  for (let i = 0; i < invalidCardsArray.length; i++) {
    const card = invalidCardsArray[i];
    const firstNum = card[0];
    if (firstNum === 3) {
      companies.push("Amex");
    } else if (firstNum === 4) {
      companies.push("Visa");
    } else if (firstNum === 5) {
      companies.push("Mastercard");
    } else if (firstNum === 6) {
      companies.push("Discover");
    } else {
      companies.push("Company not found");
    }
  }

  let dupeCompaniesRemoved = [];
  companies.forEach((company) => {
    if (!dupeCompaniesRemoved.includes(company)) {
      dupeCompaniesRemoved.push(company);
    }
  });

  return dupeCompaniesRemoved;
};