에라토스테네스의 체

getPrime.js

function getPrime(max){
    let sieve = _.fill(Array(max), true);
    let _max = Math.floor(Math.sqrt(max));
    sieve[0] = false;
    sieve[1] = false;

    for(let i = 2 ; i <= _max ; i++){
        if(sieve[i]){
            for(let j = i * 2 ; j <= max ; j += i){
                sieve[j] = false;
            }
        }
    }
    let result = [];
    sieve.forEach((check, index, arr)=>((check) && result.push(index)));

    return result;
}