function prime_checker (n) {
  if ([0,1].includes(n)) return false;
  if (n == 2) return true;
  if (n % 2 == 0) return false;
  for(let i = 3; i < n; i += 2) {
    if(n % i === 0) return false;
  }
  return true;  
}

def prime_checker(n):
    if n == 2: return True
    if n < 2 or n % 2 == 0: return False
    for i in range(3, n, 2):
        if n % i == 0: return False
    return True

def prime_checker(n):
    a = 0
    for i in range(2,n):
        if n == 2:
            return True
        elif n%i == 0:
            return False
    return True