# Credit Card Checker checkInvalidCard return question

Hello Everyone! This question is not required by the project but i cannot figure out how to do this with any amount of googling. Basically i would like to return the names of the nested arrays instead of the array itself with the function findInvalidCards.

Right now it’s returning:

``````[ [ 5, 9, 7, 1, 9, 0, 1, 7, 7, 8, 7, 7, 2, 3, 5, 4 ],
[ 3, 4, 6, 4, 3, 1, 2, 9, 3, 3, 9, 5, 5, 9, 7, 5 ],
[ 4, 1, 9, 9, 5, 4, 4, 8, 0, 6, 9, 7, 5, 7, 3 ],
[ 5, 3, 9, 7, 7, 7, 1, 6, 9, 7, 2, 1, 1, 1, 0, 6 ],
[ 4, 5, 8, 3, 8, 8, 2, 7, 7, 9, 1, 0, 2, 8, 3, 5 ],
[ 4, 1, 4, 5, 0, 3, 8, 6, 9, 1, 0, 8, 4, 4, 3 ],
[ 3, 0, 2, 6, 5, 6, 2, 6, 9, 0, 2, 0, 7, 7, 3, 1, 1, 0, 6 ],
[ 3, 9, 0, 7, 1, 2, 9, 6, 1, 7, 7, 8, 9, 2, 9, 4 ] ]
``````

But i would like it to return:

``````[[valid1], [invalid2], [mystery3], [mystery1]]

``````

How would you accomplish this?

``````// 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];

function validateCard(cc){
nDigits=cc.length
checkCard = cc.reverse()
newArr = []

for(i = 0; i< cc.length; i++){
digit = checkCard[i]
if(i % 2 != 0){
digit*=2
}
if(digit > 9){
digit -=9
}
newArr.push(digit)
}

let sum = newArr.reduce(function (a, b) {
return a + b;
}, 0);

if (sum % 10 == 0) {
return true;
} else {
return false;
}
}

function findInvalidCards(nestedArray){
const newArr = []
for (let i =0; i < nestedArray.length; i++){
if(validateCard(nestedArray[i])===false){
newArr.push(nestedArray[i])
}
}

return newArr
}

console.log(findInvalidCards(batch))

``````

Try this.

2 Likes

I love the dev community

Thank you that’s exactly what i was trying to do!

1 Like