How to check if a number is prime or not using Javascript

Question

I was trying whether I can print a number is prime or not in Javascript and I am unable to do that. Can someone please help me?

Answer 1

Just follow the piece of code provided below to check if the number is prime or not. 

Code: 

// Example program to check if a number is prime or not  

const isPrime = n => { 

  if (n === 2 || n === 3) return true; 

  if (n < 2 || n % 2 === 0) return false; 

  return isPrimeRecursive(n); 

} 

// Iterating only over odd divisors( makes no sense to iterate over even numbers). 

const isPrimeRecursive = (n, i = 3, limit = Math.floor(Math.sqrt(n))) => {   

  if (n % i === 0) return false; 

  if (i >= limit) return true; // Heureka, we have a prime here! 

  return isPrimeRecursive(n, i += 2, limit); 

} 

for (i = 0; i <= 50; i++) { 

  console.log(`${i} is ${isPrime(i) ? `a` : `not a` } prime`); 

}