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 arrRev = arr.reverse()
  for (let i = 1; i < arrRev.length; i+=2){arrRev[i] *= 2;
             
    if (arrRev[i] > 9) {
      arrRev[i] -= 9; 
      }} 
    
    let sum = 0; 
     for(let i = 0; i < arrRev.length; i++) 
         sum += arrRev[i]; 
          if (sum % 10 === 0){
           return true;} 
            else return false; 
    }

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

const invalidCardCompanies = (arr) =>{
 
 const invComp = [];

 for (let i = 0; i < arr.length; i++){

   if (arr[i][0] === 3 && invComp.indexOf('Amex') === -1){
     invComp.push('Amex'); 
     } 
   else if (arr[i][0] === 4 && invComp.indexOf('Visa') === -1){
     invComp.push('Visa');
     }
   else if (arr[i][0] === 5 && invComp.indexOf('Mastercard') === -1){
     invComp.push('Mastercard'); 
     }
   else if (arr[i][0] === 6 && invComp.indexOf('Discover') === -1){
     invComp.push('Discover'); 
     }
   else if (arr[i][0] > 6 || arr[i][0] < 3){
    console.log('Company not found.'); 
   }  
 }return invComp;
};

console.log(invalidCardCompanies(findInvalidCards(batch)))