I’m burning my brain on this project, can someone take a look a my code please?
1 - in the Luhn algorithm talk about sum the last digit (wich first we remove) with the sum of all the element of the array, so how I make this happen? I can’t find this in some codes I looked.
2 - With my currently code here some of the valids arrays keep showing invalid when I execute the function, but with my noob eyes I’m can’t see the mistake, can someone point out?
// 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 newArray = [];
let reversedArray = arr.slice(0, -1).reverse();
for(let i = 0; i < reversedArray.length; i++){
if(i % 2 !== 0) {
reversedArray[i] *= 2;
if (reversedArray[i] > 9){
reversedArray[i] -= 9;
}
}
newArray.push(reversedArray[i]);
let sum = newArray.reduce((accumulator, number) => {
accumulator + number, 0
});
if (sum % 10 === 0){
return true;
} else {
return false;
}
}
};
console.log(validateCred(valid1));
console.log(validateCred(valid2))
const findInvalidCards = arr => {
let invalidCards = [];
for (let i = 0; i < arr.length; i++) {
if (validateCred(arr[i]) === false) {
invalidCards.push(arr[i])
}
}
return invalidCards;
};
console.log(findInvalidCards(batch));
// output
true
false
[ [ 5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9 ],
[ 3, 7, 1, 6, 1, 2, 0, 1, 9, 9, 8, 5, 2, 3, 6 ],
[ 4, 5, 3, 9, 4, 0, 4, 9, 6, 7, 8, 6, 9, 6, 6, 6 ],
[ 4, 5, 3, 2, 7, 7, 8, 7, 7, 1, 0, 9, 1, 7, 9, 5 ],
[ 5, 7, 9, 5, 5, 9, 3, 3, 9, 2, 1, 3, 4, 6, 4, 3 ],
[ 3, 7, 5, 7, 9, 6, 0, 8, 4, 4, 5, 9, 9, 1, 4 ],
[ 6, 0, 1, 1, 1, 2, 7, 9, 6, 1, 7, 7, 7, 9, 3, 5 ],
[ 5, 3, 8, 2, 0, 1, 9, 7, 7, 2, 8, 8, 3, 8, 5, 4 ],
[ 3, 4, 4, 8, 0, 1, 9, 6, 8, 3, 0, 5, 4, 1, 4 ],
[ 5, 4, 6, 6, 1, 0, 0, 8, 6, 1, 6, 2, 0, 2, 3, 9 ],
[ 4, 9, 2, 9, 8, 7, 7, 1, 6, 9, 2, 1, 7, 0, 9, 3 ],
[ 4, 9, 1, 3, 5, 4, 0, 4, 6, 3, 0, 7, 2, 5, 2, 3 ] ]
.
