how to check if number is prime in js code example
Example 1: js code to check whether a number is prime or not
function isPrime(n)
{
if (n < 2)
return false;
if (n == 2)
return true;
var maxDiv = Math.sqrt(n);
for(var i = 2; i <= maxDiv; i++)
{
if (n % i == 0)
{
return false;
}
}
return true;
}
println(2, " is prime? ", isPrime(2));
println(3, " is prime? ", isPrime(3));
println(4, " is prime? ", isPrime(4));
println(5, " is prime? ", isPrime(5));
println(9, " is prime? ", isPrime(9));
Example 2: Javascript prime number check
function is_prime (n) {
if (n < 3) return n > 1;
else if (n % 2 === 0 || n % 3 === 0) return false;
else if (n < 25) return true;
let i = 5;
while (i * i <= n ) {
if (n % i === 0 || n % (i + 2) === 0) return false;
i += 6;
}
return true;
}