Sometimes, we want to check if a number is prime in JavaScript.
In this article, we’ll look at how to check if a number is prime in JavaScript.
How to check if a number is prime in JavaScript?
To check if a number is prime in JavaScript, we can use a loop.
For instance, we write
const isPrime = (num) => {
for (let i = 2, s = Math.sqrt(num); i <= s; i++) {
if (num % i === 0) {
return false;
}
}
return num > 1;
};
to define the isPrime function.
In it, we loop from 2 to the square root of num.
In the loop body, we check if num can be evenly divisible by i with num % i === 0.
And if it’s true, we return false since it’s not prime.
If it’s evenly divisible by nothing, we return true.
Conclusion
To check if a number is prime in JavaScript, we can use a loop.
