How to Determine Prime Numbers in JavaScript

In JavaScript, identifying prime numbers is a common programming task. A prime number is a positive integer greater than 1 that is not divisible by any other positive integer except 1 and itself.

Solution 1: Naive Approach

The provided code snippet offers a simple way to check if a number is prime:

let inputValue = 7;
let isPrime = inputValue == 1 ? false : true;

for (let i = 2; i 
Time Complexity: O(sqrt(n))
Space Complexity: O(1)
Solution 2: Efficient Approach
An improved approach for checking prime numbers is:
const isPrime = num => {
  for (let i = 2, s = Math.sqrt(num); i  1;
};
This code takes advantage of the fact that if a number is not prime, it has a factor that is less than or equal to its square root. By checking for factors up to the square root, we can efficiently eliminate potential factors.
Time Complexity: O(sqrt(n))
Space Complexity: O(1)