sieve of eratosthenes in javascript
const num = 100;
const findPrimes = (num = 10) => {
const numArr = new Array(num + 1);
numArr.fill(true);
numArr[0] = numArr[1] = false;
for (let i = 2; i <= Math.sqrt(num); i++) {
for (let j = 2; i * j <= num; j++){
numArr[i * j] = false;
}
}
return numArr.reduce((acc, val, ind) => {
if(val){
return acc.concat(ind);
}else{
return acc;
};
},[]);
};
console.log(findPrimes(num));