深入挖掘PHP8的实用功能及其应用案例

declare(strict_types=1);

function calculateFibonacci(int $n): int
{
    if ($n <= 0) {
        return 0;
    } elseif ($n == 1) {
        return 1;
    } else {
        return calculateFibonacci($n - 1) + calculateFibonacci($n - 2);
    }
}

$start = microtime(true);

echo calculateFibonacci(30) . "
";

$end = microtime(true);
$executionTime = $end - $start;

echo "Execution time: " . $executionTime . " seconds
";

class Car {
    public string $brand;
    public string $model;
    public int $year;
    
    public function __construct(string $brand, string $model, int $year) {
        $this->brand = $brand;
        $this->model = $model;
        $this->year = $year;
    }
}

$car = new Car("BMW", "X5", 2021);
echo "Brand: " . $car->brand . "
";
echo "Model: " . $car->model . "
";
echo "Year: " . $car->year . "
";

interface Logger {
    public function log(string $message);
}

function logMessage(string $message, Logger $logger) {
    $logger->log($message);
}

logMessage("This is a log message", new class implements Logger {
    public function log(string $message) {
        echo $message . "
";
    }
});

function calculateSum(int $a, int $b): int {
    return $a + $b;
}

echo calculateSum(1, 2);