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 invalidCards=[];
const validateCred = array => {
  let sum=0;
  let flag = true;
  for(let i= array.length-1;i>=0;i--){
    if(flag){
      //console.log(array[i] +' ');
      sum  = sum + array[i];
      flag = false;
        }
        else {
          let val1  = array[i]*2;  
          if( val1 > 9)
          {
            //console.log((val1-9) +' ');
          sum  = sum + (val1) - 9;
          }
          else
          {
            //console.log(array[i] +' ');
            sum=sum+ val1;
          }
          flag = true;;
        }
  }
  //console.log(`sum=${sum}`);
  return (sum%10 === 0);

};
//console.log(validateCred(valid1));




//find Invalid cards

const findInvalidCards = array => {
const invalidCards=[];
for(let i=0 ;i < array.length ; i++){
  let value = validateCred(array[i]);
  if(value === false){
    invalidCards.push(array[i]);
  }
}
return invalidCards;
};
//console.log(findInvalidCards(batch));


//idInvalidCardCompanies  ia a higher-order function which takes findInvaidCars function ,batch as parameters

const idInvalidCardCompanies = (funcFindInvalidCards, arryBatch) => {
  let arrayOfCompanies= [];
  const array = funcFindInvalidCards(arryBatch);
  for(i=0;i<array.length;i++){
    let firstNumber = array[i][0];
    switch(firstNumber) {
      case 3:
      if(arrayOfCompanies.indexOf('Amex(American Express)')<0){
        arrayOfCompanies.push('Amex(American Express)');
        }
        break;  
        case 4:
        if(arrayOfCompanies.indexOf('Visa') < 0){
        arrayOfCompanies.push('Visa');
        }
        break;
        case 5:
        if(arrayOfCompanies.indexOf('Mastercard') < 0) {
        arrayOfCompanies.push('Mastercard');
         }
        break;
        case 6:
        if(arrayOfCompanies.indexOf('Discover') < 0){
        arrayOfCompanies.push('Discover');
         }
        break;     
        default:
        console.log("Company Not Found")
        break;                   
    }
  }
  return arrayOfCompanies;
};


const produceArray = stringArray => {
  return parseInt(stringArray);
};

//console.log(validateCred(valid1));
//findInvalidCards(batch);


console.log(idInvalidCardCompanies(findInvalidCards, batch));
// gives the companynames of invaidcards