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 totalSum = 0;
  let number;
  for (let i = array.length-1; i >= 0; i-=2) {
    totalSum += array[i];
  };
  for (let j = array.length-2; j >= 0; j-=2) {
    number = array[j] * 2;
    if (number > 9) {
      number -= 9;
      totalSum += number
    } else {
      totalSum += number
    };
  };
  if (totalSum % 10 === 0) {
    return true
  } else {
    return false
  }; 
};

const findInvalidCards = array => {
  let newArray = [];
  for (let i = 0; i < array.length; i++) {
    if (!validateCred(array[i])) {
      newArray.push(array[i])
    }
  };
  return newArray;
};

const idInvalidCardCompanies = array => {
  const inputArray = findInvalidCards(array);
  let companiesArray = [];
  for (let i = 0; i < inputArray.length; i++) {
    if (inputArray[i][0] === 3) {
      companiesArray.push('Amex');
    } else if (inputArray[i][0] === 4) {
      companiesArray.push('Visa')
    } else if (inputArray[i][0] === 5) {
      companiesArray.push('Mastercard')
    } else if (inputArray[i][0] === 6) {
      companiesArray.push('Discover')
    } else {
      companiesArray.push('Company not found')
    };
  };
  return companiesArray.filter((item, index) => companiesArray.indexOf(item) === index);
};


console.log(validateCred(valid1)); // Should print true
console.log(validateCred(invalid1)); // Should print false

console.log(findInvalidCards([valid1, valid2, valid3, valid4, valid5]));// Shouldn't print anything
console.log(findInvalidCards([invalid1, invalid2, invalid3, invalid4, invalid5])); // Should print all of the numbers

console.log(idInvalidCardCompanies([invalid1])); // Should print['visa']
console.log(idInvalidCardCompanies([invalid2])); // Should print ['mastercard']
console.log(idInvalidCardCompanies(batch)); // Find out which companies have mailed out invalid cards