Codecademy export

main.js

// All valid credit card numbers
const valid2 = [5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9];
const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8];
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 doubleCheck = []
  for (i = array.length-2; i>=0; i-= 2) {
    let double = array[i]*2
    if (double > 9) {
      doubleCheck.push(double-9)
    } else {
      doubleCheck.push(double)
    }
  }

  let remainingNum = []
  for (i = array.length-1; i>=0; i-= 2) {
    remainingNum.push(array[i])
  }

  let allDigits = doubleCheck.concat(remainingNum)

  let sum = 0
  allDigits.forEach(num => {
    sum += num
  })

  if (sum % 10 == 0) {
    return true
  } else {
    return false
  }
}

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

const idInvalidCardCompanies = invalidNumbers => {
  let companies = []
  for (let i=0;i<invalidNumbers.length;i++) {
    if (invalidNumbers[i][0] === 3) {
      companies.push('Amex (American Express)')
    } else if (invalidNumbers[i][0] === 4) {
      companies.push('Visa')
    } else if (invalidNumbers[i][0] === 5) {
      companies.push('Mastercard')
    } else if (invalidNumbers[i][0] === 6) {
      companies.push('Discover')
    } else if (invalidNumbers[i][0] != 3 || invalidNumbers[i][0] != 4 || invalidNumbers[i][0] != 5 || invalidNumbers[i][0] != 6) {
      return 'Company not found'
    }  
  }
  
  let final = []
  companies.forEach(company => {
    if (!final.includes(company)) {
      final.push(company)
    }
  })

  return final
}



console.log(idInvalidCardCompanies(findInvalidCards(batch)))