I don’t understand this project. I mean are valid arrays really valid? because each time I log an array called with `validateCred`

function, I get invalid and my function is:

```
const reduce = (accumateValue, currentValue) => accumateValue + currentValue;
// Add your functions below:
const validateCred = arr => {
for (let i= arr.length - 2; i >= 0; i--) {
arr[i] = arr[i] * 2
if (arr[i] > 9 ) {
arr[i] -= 9;
};
}; // i loop end
const array2 =arr.reduce(reduce);
const remainder = array2 % 10;
if (remainder == 0) {
return "valid"
} else {
return "invalid"
}
return remainder
}; // function end
```

Please help.