PHP 函数中变量类型与错误处理的关系？

function functionName(type $parameterName) { ... }

function addNumbers(int $num1, int $num2) {
    return $num1 + $num2;
}

try {
    // 尝试执行代码块
} catch (TypeError $e) {
    // 在发生类型错误时执行此代码块
}

try {
    addNumbers('1', 2); // 抛出 TypeError 因为 '1' 不是 int
} catch (TypeError $e) {
    echo "TypeError: " . $e->getMessage();
}

TypeError: Argument 1 passed to addNumbers() must be of the type int, string given

function calculateAge(string $birthdate, string $currentDate): int {
    // 将字符串日期转换为时间戳
    $birthdate_timestamp = strtotime($birthdate);
    $currentDate_timestamp = strtotime($currentDate);

    // 计算年龄差异（以秒为单位）
    $ageDifference = $currentDate_timestamp - $birthdate_timestamp;

    // 将年龄差异转换为年
    $age = floor($ageDifference / (60 * 60 * 24 * 365));

    return $age;
}

try {
    $age = calculateAge(1990, 2023); // 抛出 TypeError 因为 1990 不是字符串
} catch (TypeError $e) {
    echo "TypeError: " . $e->getMessage();
}

TypeError: Argument 1 passed to calculateAge() must be of the type string, integer given