primes/primes.js

let max = process.argv[2];
for(cnt = 3; cnt <= max; cnt += 2) {
    let sq = Math.round(Math.sqrt(cnt));
    let isPrime = true;
    for(i=3; i<=sq; i+=2) {
        if(cnt % i == 0) {
            isPrime = false
            break;
        }
    }
    if (isPrime) {
        console.log(cnt);
    }
}