# 120. create `isPrime()`

JavaScriptAlgorithmShare

easy - accepted / - tried

A Prime number is a natural number greater than 1 that is divisible only by itself and 1, such as 2,3,5....

You are asked to implement `isPrime()`

to check if a number is prime.

**Follow-up**

What is the time cost of your implementation ? can you improve your approach to have the fewest comparisons?