set of all primes as a sumation code example

Example: Sum All Primes

// I will update this code later, cause this is already very tasky, 
// bad performance(Two loops inside a loop) // Very bad, but it works

const sumPrimes = num => {
  const divisor = []
  for(let i = 2; i <= num; i++){
    let factorial = [], j = 1, num = []
    while(j <= i){ factorial.push(j); j++ }

    factorial.forEach(elem => {
      if(i % elem === 0) num.push(elem) 
    })
    
    if(num.length === 2) divisor.push(i)
  }

  return divisor.reduce((acc, cur) => acc + cur);
}

sumPrimes(977);