Check if number is Prime or not

is-prime.js

function isPrime(num) {
  const root = Math.sqrt(num);

  if (root <= 1) {
    return false;
  }

  for (let i = 2; i <= root; i++) {
    if (num % i === 0) {
      return false;
    }
  }
  
  return true;
}

for (let i = 0; i < 100; i++) {
  console.log(i, isPrime(i));    
}