Credit Card Checker

Projects
1

Hello! Day 2 working on this project, feeling like a dummy)) Here is what I have so far, I want to know if I am on a right track.

function validateCred(array){
  let newArray = [];
for(let i = array.length - 1;i >= 0; i-=2){
  let doubleValue = array[i] * 2
  if(doubleValue < 9){
    doubleValue =- 9;
  }
  newArray.push(doubleValue);
  let sum = newArray.reduce((a, b)=> a + b, 0);
  if(sum % 10 === 0){
    return true;
  }else{
    return false;
  };
}
1 Like
2

Did you copy the code to the forum correctly?

there is a missing } to close your function. Also, I would loop over all the values first, adding them to new array

then after the loop, sum all the numbers once/one time. you currently sum every iteration of the loop

also, looking at this visual representation:

https://content.codecademy.com/PRO/independent-practice-projects/credit-card-checker/diagrams/cc%20validator%20diagram%201.svg

you can see we still need to all the numbers, so you can’t just skip every other number.

1 Like
3

Thank you for help!
Fixed the bracket. How could I miss it ! [facepalm]
I tried to look around how to avoid adding every other value to newArray. This is what I am doing atm :

function validateCred(array){
  const newArray = [];
for(let i = array.length - 1;i >= 0; i--){
  let doubleValue = array[i];
  if((i % 2) === 0){
    doubleValue *= 2;
  }
    if(doubleValue < 9){
      doubleValue =- 9;
    }
  }
  newArray.push(doubleValue);
  let sum = newArray.reduce((a, b)=> a + b, 0)
  if(sum % 10 === 0){
    return true;
  }else{
    return false;
  };
}
4

this line:

newArray.push(doubleValue);

should most certainly be in the loop. We want the loop to add the numbers to newArray. Or you could simply do:

const total = 0;
for(let i = array.length - 1;i >= 0; i--){
  let doubleValue = array[i];
  if((i % 2) === 0){
    doubleValue *= 2;
  }
    if(doubleValue < 9){
      doubleValue =- 9;
    }
   total += doubleValue;
  }

why use an array, while we can sum the values directly?

If you need more help, please also provide the exercise url

5

Thank you very much!