Hello, I’m working on the Challenge Project: Credit Card Checker exercise and I’m a bit stuck on what it seems like a loop that goes on forever and crashes.
// 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:
function validateCred(arr) {
let lastElement = arr.length - 1;
var sum = 0;
var double = 0;
for (i = arr.length - 1; i >= 0; i--) {
if (lastElement % 2 === 0) {
if (i === arr.length - 1) {
sum = sum + arr[i];
} else if (i % 2 === 1) {
double = arr[i] * 2;
if (double > 9) {
double = double - 9;
sum = sum + double;
} else if (double <= 9) {
sum = sum + double;
}
} else if (i % 2 === 0) {
sum = sum + arr[i];
}
} else if (lastElement % 2 === 1) {
if (i === arr.length - 1) {
sum = sum + arr[i];
} else if (i % 2 === 0) {
double = arr[i] * 2;
if (double > 9) {
double = double - 9;
sum = sum + double;
} else if (double <= 9) {
sum = sum + double;
}
} else if (i % 2 === 1) {
sum = sum + arr[i];
}
}
}
if (sum % 10 === 0) {
return true;
} else return false;
}
//console.log(validateCred(mystery5));
//const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8]
function findInvalidCards(arr) {
var invalidCards = [];
for (i = 0; i < arr.length; i++) {
if (!validateCred(arr[i])) {
invalidCards.push(arr[i]);
}
}
}
//findInvalidCards(batch);
Everything goes well until I want to use the last function - findInvalidCards(). As soon as I run the last commented line, it goes in a loop.
Can anyone help me find what I’m doing wrong?