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 verificationArray =[];
  if(array.length%2 == 0){
   for (let i = array.length - 1; i>=0; i--){
   if(i%2 == 0 ){
   let newNumber = (array[i]*2);
      if(newNumber>9){
      newNumber = newNumber - 9;
      verificationArray.unshift(newNumber)
      }else{verificationArray.unshift(newNumber)}
    }else{verificationArray.unshift(array[i])}
   }
  }else{
      for (let i = array.length - 1; i>=0; i--){
   if(i%2 !== 0 ){
   let newNumber = (array[i]*2);
      if(newNumber>9){
      newNumber = newNumber - 9;
      verificationArray.unshift(newNumber)
      }else{verificationArray.unshift(newNumber)}
    }else{verificationArray.unshift(array[i])}
   }
  }
  const sum = verificationArray.reduce((accumulator,currentValue) =>{
    return accumulator + currentValue
  })
 return sum%10 === 0 ? true : false
}

const findInvalidCards = array => {
let invalidCards = []
let validCards= []
 for (card of array){
   if(!validateCred(card)){
     invalidCards.push(card)
   }else{ validCards.push(card)}
 }
return invalidCards
}

const idInvalidCardCompanies = array =>{
  let cards =findInvalidCards(array)
  var companies = []
  for(card of cards){
      switch(card[0]){
      case 3:
      if(!companies.includes('Amex')){
          companies.push('Amex')
      }
      break;
      case 4: 
      if(!companies.includes('Visa')){
      companies.push('Visa')
      }
      break;
      case 5:
      if(!companies.includes('MasterCard')){
      companies.push('MasterCard')
      }
      break;
      case 6:
      if(!companies.includes('Discover')){
      companies.push('Discover')
      }
      break;
   
    }
  }
  return companies
}
console.log(idInvalidCardCompanies(batch))