<?php

function isStrongPassword(string $password): bool {
    // Requires at least one uppercase letter, one lowercase letter, one digit,
    // one special character, and a minimum length of 8 characters.
    $passwordRegex = '/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};\':\",.<>\/?]).{8,}$/';
    return preg_match($passwordRegex, $password) === 1;
}

echo "StrongPassword123! is strong: " . (isStrongPassword('StrongPassword123!') ? 'Yes' : 'No') . "
";
echo "weakpass is strong: " . (isStrongPassword('weakpass') ? 'Yes' : 'No') . "
";
echo "NoDigits! is strong: " . (isStrongPassword('NoDigits!') ? 'Yes' : 'No') . "
";
echo "NoSpecial123 is strong: " . (isStrongPassword('NoSpecial123') ? 'Yes' : 'No') . "
";

?>