<?php
function maybe_exit(int $code = 0): void {
    if ($code > 0) {
        exit($code);
    }
}

$i = 0;
while ($i < 4) {
    if ($i === 1) {
        $i++;
        continue;
    }
    if ($i === 3) {
        break;
    }
    echo $i;
    $i++;
}
echo "\n";
maybe_exit();
