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 sum = 0
  let checkMeth = arr.length % 2 === 0
  if (checkMeth === true){
  for(let i = arr.length -1; i >= 0; i--){
    if(i % 2 !== 0){
      sum += arr[i]
    } else{
      if(arr[i] * 2 > 9){
        sum += arr[i] * 2 - 9
      } else {
        sum += arr[i] * 2
      }
    }
  }
} else{
  for(let i = arr.length -1; i >= 0; i--){
    if(i % 2 === 0){
      sum += arr[i]
    } else{
      if(arr[i] * 2 > 9){
        sum += arr[i] * 2 - 9
      } else {
        sum += arr[i] * 2
  }
}
}
}
if (sum % 10 === 0){
  return true
}else{
  return false
}
}
const findInvalidCards = arr2 => {
  let invArr = []
  for (let i = 0; i < arr2.length; i++){
    if(validateCred(arr2[i]) === false){
     invArr.push(arr2[i])
    }
  } return invArr
}
//console.log(findInvalidCards(batch))

const idInvalidCardCompanies = arr3 => {
  let compArr = []
  for(let i = 0; i < arr3.length; i++){
    if (arr3[i][0] === 3 && !compArr.includes('Amex')){
      compArr.push('Amex')
    } else if (arr3[i][0] === 4 && !compArr.includes('Visa')){
      compArr.push('Visa')
    } else if (arr3[i][0] === 5 && !compArr.includes('MasterCard')){
      compArr.push('MasterCard')
    } else if (arr3[i][0] === 6 && !compArr.includes('Discover')){
      compArr.push('Discover')
    }
  }return compArr
}
//console.log(idInvalidCardCompanies(findInvalidCards(batch)))