Here is the interview question prompt, presented for reference.

You're given a number `n`

. Can you write a method `sumOfAllPrimes`

that finds all prime numbers smaller than or equal to `n`

, and returns a sum of them?

For example, we're given the number `15`

. All prime numbers smaller than `15`

are:

`2, 3, 5, 7, 11, 13`

They sum up to `41`

, so `sumOfAllPrimes(15)`

would return `41`

.

`n`

will always be a non zero positive integer <=`100000`

- Expected time complexity :
`O(nlogn)`

- Expected space complexity :
`O(n)`

You can see the full challenge with visuals at this link.

**Challenges**
â€¢ Asked 11 months ago by Anonymous

This is the main discussion thread generated for Sum All Primes.

sumOfAllPrimes(15) should return 65, as the question asks for all prime numbers smaller than or equal to n correct?

Never mind I misread the question

This solution is O(n log n), right? But O(1) in space

```
function sumOfPrimes(n) {
let total = 0;
for(let i = 2; i <= n; i++) {
if(isPrime(i)) {
total += i;
}
}
return total;
}
function isPrime(n) {
for(i = 2; i <= Math.sqrt(n); i++) {
if(n % i === 0) return false;
}
return true;
}
```