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 => {
  let num = arr;
  for(let i = num.length - 2; i >= 0; i -= 2) {
    num[i] = num[i] * 2;
    if(num[i] > 9) {
      num[i] = num[i] - 9;
    }
  }
  let newArr = num.reduce((accumulator, currentValue) => {
    return accumulator + currentValue;
  })
 return newArr % 10 === 0 ? 'Valid' : 'Invalid';
}




const findInvalidCards = arr => {
  let invalidCards = arr.filter(element => {
    return validateCred(element) === 'Invalid'
  })
  return invalidCards;
};


const idInvalidCardCompanies = arr => {
  let invalidCards = findInvalidCards(arr)
  let cardCompany = invalidCards.map(element => {
    switch(element[0]) {
      case 3:
      return 'Amex';
      break;
      case 4:
      return 'Visa';
      break;
      case 5:
      return 'Mastercard';
      break;
      case 6:
      return 'Discover';
      break;
      default:
      return 'Company not found!'
    }
  })
  let removeDuplicates = cardCompany.filter((value, index) => cardCompany.indexOf(value) === index)
  return removeDuplicates
};

console.log(idInvalidCardCompanies(batch));