Evaluate if number is prime.

gistfile1.txt

<?php

function isPrime(int $number): bool
{
    $boundary = floor(sqrt($number));
    $i = 2;
    do {
        if (($number % $i) === 0) {
            return false;
        }
        
        $i++;
    } while ($i <= $boundary);

    return $number >= 2;
}

$number = 3;
var_dump(isPrime($number));