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:
function validateCred(array) {
  /*We'll place the handled numbers here upon iterating the provided array*/
  let iteratedArray = [];
  /*Used to determine if iterated number needs doubling*/
  let counter = 1;
  let digit = 0;
  for (let i = array.length - 1; i >= 0; i--) {
    /*Counter starts from 1, so last number in array doesn't get doubled*/
    if(counter % 2 === 0) {
      /*Determining how to handle number after passing "every other digit" test.*/
      digit = array[i] * 2 > 9 ? (array[i] * 2) - 9 : array[i] * 2
      iteratedArray.unshift(digit);
    } else {
      iteratedArray.unshift(array[i])
    }
    counter += 1;
  }
  //Summing the members of iteratedArray
  let sum = iteratedArray.reduce((previousValue, currentValue) => {
    return previousValue + currentValue;
  });
  if (sum % 10 === 0){
    return true;
  } else {
    return false;
  }
}

function findInvalidCards(array) {
  let invalidCardArray = [];
  for (card in array) {
    if (validateCred(array[card]) === false){
      invalidCardArray.push(array[card]);
    }
  }
  return invalidCardArray;
}

function idInvalidCardCompanies(array) {
  let companyArray = [];
  //Iterate through invalid cards array
  for(card in array) {
    let company;
    /*First number of card determines company, so assigning company variable according to iterated card*/
    switch(array[card][0]) {
      case 3:
      company = 'Amex (American Express)';
      break;
      case 4:
      company = 'Visa';
      break;
      case 5:
      company = 'Mastercard';
      break;
      case 6:
      company = 'Discover';
      break;
      default:
      company = 'Company not found';
    }
    //If company is not in companyArray, it gets pushed in
    if (companyArray.indexOf(company) === -1) {
      companyArray.push(company);
    }
  }
  return companyArray;
}
let invalidCards = findInvalidCards(batch);
console.log(idInvalidCardCompanies(invalidCards));