Prime numbers & factors

primes-and-factors.js

export function listFactors(target) {
  let primes = listPrimes(target);
  let factors = [];
  for (let i = 0; i < primes.length; i++) {
    if ((target % primes[i]) === 0) factors.push(primes[i]); 
  }
  return factors;
}

// list all prime numbers up to n
export function listPrimes(n) {
  let primes = [];
  for (let i = 2; i < n; i++) {
    if (isPrime(i)) primes.push(i);
  }
  return primes;
}

function isPrime(n) {
  for (let i = 2; i < n; i++){
    if ((n % i) === 0) return false;
  }
  return true;
}