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 = arr => {
  const slicedArr = arr.slice(); //Make a copy of Array
  const poppedItem = slicedArr.pop(); // Remove last element(Check digit)
  let ModuloArr = [];
  //Created a reverse for-loop. This for loop doubles elements in the loop.
  for (let i = slicedArr.length - 1; i >= 0; i -= 2) {
    slicedArr[i] *= 2;  
    if (slicedArr[i] > 9){
      slicedArr[i] -= 9
    } ModuloArr.push(slicedArr[i])
  } 
  //This second for loop adds the other part of the array that is not doubled to the ModuloArr
  for (let j = slicedArr.length - 2; j >= 0; j -= 2) {
    if (slicedArr[j] > 9) {
      slicedArr[j] -= 9
    } ModuloArr.push(slicedArr[j])
    } 
  ModuloArr.push(poppedItem)
  let arrSum = 0;
  for (let k = 0; k < ModuloArr.length; k++) {
    arrSum += ModuloArr[k]  
  } return arrSum % 10 === 0
};

const findInvalidCards = arr => {
  let invalidCards = [];
  for (let e = 0; e < arr.length; e++) {
    if(validateCred(arr[e]) === false) {
      invalidCards.push(arr[e])
    }
} return invalidCards;
}
const invalidArrId = findInvalidCards(batch) 
//console.log(invalidArrId);

const idInvalidCardCompanies = arr => {
  let cardCompanies = [];
  for (let i = 0; i < arr.length; i++) {
    if (arr[i][0] === 3) {
      cardCompanies.push('Amex')
  } else if (arr[i][0] === 4) {
      cardCompanies.push('Visa')
  } else if (arr[i][0] === 5) {
      cardCompanies.push('Mastercard')
  } else if (arr[i][0] === 6) {
      cardCompanies.push('Discover')
  } else {
    cardCompanies.push('Company not found')
  }
  } return cardCompanies
}
const invalidCards = idInvalidCardCompanies(invalidArrId)
console.log([...new Set(invalidCards)]) //Returns unique items in an array