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:

//Declare a variable to hold the sum of all the relevant digits
let digitSum = 0;

//Declare an empty array to hold the digits to sum
let sumArray = [];

//Declare an empty array to hold a nested array of invalid credit cards
let invalidCards = [];

const validateCred = (array) => {
  //Pass the array to the function that populates the array that holds the numbers to be summed
  populateSumArray(array);

  //Pass sumArray into sumValue 
  let totalSum = sumValue(sumArray);
  console.log(`totalSum: ${totalSum}`);

  //Pass totalSum into isValid
  const isCardValid = isValid(totalSum);
  console.log(`isCardValid: ${isCardValid}`);

  //If the card is not valid, return the original card array
  if(!isCardValid){
    console.log(`Invalid card array: ${array}`);
    invalidCards.push(array);
  }
}

const populateSumArray = (array) => {
  //Receive an array as an arguement.  Start at the rightmost digit and add it to a new array.  Iterate to the left and double every other digit. Check if the doubled value is greater than 9.  If so, subtract 9 from it before you add it to the array
  //Log the array passed to populateSumArray
  console.log(`Input array: ${array}`); 
  
  //Empty the sumArray before processing this card number
  sumArray = [];
  
  //Determine if the length of the array is odd or even. If it is even, double every even index number. If it is odd, double every odd index number
  //Even array length
  if(array.length % 2 == 0){
    console.log(`This array has ${array.length} digits, an even number`)
    //Iterate through the array
    for (i = array.length - 1; i >= 0; i--) {
      //Double every even index number
      if(i % 2 == 0) {
        //If the doubled number is greater than 9, subtract 9 from it's value before pushing it to sumArray
        if(array[i] * 2 > 9){
          console.log(`array[${i}] * 2 - 9: ${(array[i] * 2) - 9}`);
          sumArray.push((array[i] * 2) - 9);
        }
        //...otherwise, push the doubled number to sumArray
        else {
          console.log(`array[${i}] * 2: ${(array[i] * 2)}`);
          sumArray.push((array[i] * 2));
        }
      } 
      //Push every odd index number without doubling
      else {
        console.log(`array[${i}]: ${array[i]}`)
        sumArray.push(array[i]);
      }
    }
    // console.log(`Returning sumArray: ${sumArray}`);
    // return sumArray;
  } 
  //Odd array length
  else {
    console.log(`This array has ${array.length} digits, an odd number`)
    //Iterate through the array
    for (i = array.length - 1; i >= 0; i--) {
      //Double every odd index number
      if(i % 2 != 0) {
        //If the doubled number is greater than 9, subtract 9 from it's value before pushing it to sumArray
        if(array[i] * 2 > 9){
          console.log(`array[${i}] * 2 - 9: ${(array[i] * 2) - 9}`);
          sumArray.push((array[i] * 2) - 9);
        }
        //...otherwise, push the doubled number to sumArray
        else {
          console.log(`array[${i}] * 2: ${(array[i] * 2)}`);
          sumArray.push((array[i] * 2));
        }
      } 
      //Push every even index number without doubling
      else {
        console.log(`array[${i}]: ${array[i]}`)
        sumArray.push(array[i]);
      }
    }
  } 
}

//Take an arguement of sumArray after doubling and sum the digits and test for the validity of the number
//Sum the values in sumArray
const sumValue = (doubledArray) => {
  //console.log(`doubledArray: ${doubledArray}`);
  const returnValue = doubledArray.reduce((previousValue, currentValue) => {
    //console.log(`previousValue: ${previousValue}`);
    //console.log(`currentValue: ${currentValue}`);
    const returns = previousValue + currentValue;
    //console.log(`returns: ${returns}`);
    return returns;
  });
  return returnValue;
}

//Take the value of sumValue and divide by 10. If remainer == 0 the card is valid, if it != 0 it's invalid
const isValid = (summedValue) => {
  //console.log(`summedValue: ${summedValue}`);
  if(summedValue % 10 == 0) {
    return true;
  } else {
    return false;
  }
}




//
const findInvalidCards = (nestedArray) => {
  

  //Iterate through the nested array checking the validity of each card array saving the result to invalidCards
  batch.filter(validateCred);
  
  console.log(`invalidCards: `);
  console.log(invalidCards);
}

const idInvalidCardCompanies = (knownInvalidCards) => {
  //Return an array of companies that have issued invalid cards
  const invalidCompanies = [];
  //Iterate through the knownInvalidCards array and check the first digit of each nested array
  //Push the company name to an array
  //Return this array with no duplicates
  //If the number is not in the list of companies return a message saying “Company not found”
  
  
  const checkFirstNumber = (element) => {
    switch (element[0]) {
      case 3:
        if(!invalidCompanies.includes('Amex')){
          invalidCompanies.push('Amex');
        }
        break;
      case 4:
        if(!invalidCompanies.includes('Visa')){
          invalidCompanies.push('Visa');
        }
        break;
      case 5:
        if(!invalidCompanies.includes('Mastercard')){
          invalidCompanies.push('Mastercard');
        }
        break;
      case 6:
        if(!invalidCompanies.includes('Discover')){
          invalidCompanies.push('Discover');
        }
        break;
      default: 
        console.log('Company not found');
    }
  }
  knownInvalidCards.forEach(checkFirstNumber);
  
  console.log(invalidCompanies);
  return invalidCompanies;
}



//Pass the nested array of credit card numbers to the findInvalidCards function
findInvalidCards(batch);

//Get the names of the companies issuing invalid cards
idInvalidCardCompanies(invalidCards);
//Test the validateCred function on the provided arrays
//batch.forEach(validateCred);

//Test the validateCred function on specific arrays
// console.log(`${batch[0]}`);
// validateCred(batch[0]);