I’m very new to JavaScript so forgive me if the following is very “noob-y”:
So I’ve been working on the Credit Card Checker project and have gotten myself stuck.
I’ve created a function that determines whether or not the card number is valid and it works great. The problem shows up when trying to create a function that will use the batch array to go through the previous function to check if each individual card is valid or not.
In the first function, I have it logging the sum of each card number after the Luhn algorithm, and saying whether it’s valid or not.
When running the new function, I can see every sum is being added onto the last, rather than staying separate.
I’m assuming I did something wrong with how I’m finding the sum of the numbers after the Luhn algorithm, I just can’t seem to get anything working correctly.
Any help is appreciated, thanks!
My code:
// 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:
let sum = 0;
let array = [];
const validateCard = (card) => {
checkCard = card.reverse();
for (let i = 0 ; i < checkCard.length ; i++)
{
if ( i % 2 !== 0 ) {
checkCard[i] = checkCard[i] * 2
if (checkCard[i] > 9) {
checkCard[i] = checkCard[i] - 9;
}
}
sum = sum + checkCard[i];
}
console.log(sum);
if (sum % 10 === 0) {
console.log('Card Valid')
}
else {
console.log('Card Invalid')
}
}
const findInvalidCards = (cardArray) => {
for (let j = 0 ; j < cardArray.length ; j++)
{
validateCard(cardArray[j])
}
}
findInvalidCards(batch)