How to check if a given integer is a prime number in JavaScript

In this Article we will go through how to check if a given integer is a prime number only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const isPrime = num => (num > 1) && Array(Math.floor(Math.sqrt(num)) - 1).fill(0).map((_, i) => i + 2).every(i => num % i !== 0);