Sieve of Eratosthenes - Javascript

sieveoferatosthenes.js

const sieveofetathothese = (n) => {
  // Create a boolean array that holds true for all the range of n
  let prime = [];
  // initialize the first non-prime number which is 2
  let p = 2;
  // populate array with the boolean of true
  for (let i = 0; i <= n; i++) prime.push(true);
  
  // While the multiples of the current value of p is not more than the number n
  while(p * p <= n) {
    // If the current item of p is still true;
    if(prime[p] === true) {
      // For all multiples of the item swap it to false
      // If p = 2; thus p * p is 4
      // i = 4; if n = 10
      for (let i = p * p; i <= n; i += p) {
        // make prime[4] since i is currently 4 then increment it with the value of p
        prime[i] = false;
        
        // since value of p is 2 then i increases to i+p = 6 (4 + 2);
        // thus falsilfies all multiples of p that is less than n
      }
    }
    // increment p Eg is p = 2; increment to 3
    p++;
  }

  for(let k = 2; k <= n; k++) {
    // log all true items in the booleen array
    if(prime[k]) console.log(k)
  }
}

sieveofetathothese(10);