I was practicing in CodeWars with katas that I have already solved before. Here is the problem:

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Finish the solution so that it returns the sum of all the multiples of 3 or 5 below the number passed in.

Additionally, if the number is negative, return 0.

Note: If the number is a multiple of both 3 and 5, only count it once.

It’s a very simple kata, but when I tried to solve it my solution didn’t work. I checked my previous solution and I notice that is almost identical to my current one. However, the first code return the correct output and the second doesn’t.

First solution (it works)

function solution(number){
  
  let sum = 0;
  
  if (number < 0) {
    return 0;
  }
  
  for (i = 1; i < number; i++) {
    if (i % 3 === 0 || i % 5 === 0) {
      sum += i;
    }
  }
  return sum;
}

Second solution (doesn’t work)

function solution(number){
  
  let count = 0;
  
  if (number < 0) {
    return 0;
  }
  
  for (i = 1; i < number; i++) {
      if (i % 3 === 0 || i % 5 === 0) {
        count += 1;
      }
  }
  return count;
}

What am I missing?

The test is with number 10. It should return 23, but in the second code it returns 4. I tried both codes in the console.