What are the best practices for handling object instances across multiple PHP files?

When dealing with object instances across multiple PHP files, it's important to ensure consistency and avoid conflicts. One way to achieve this is by using a singleton pattern to ensure that only one instance of the object exists throughout the application. By using a singleton pattern, you can easily access and manipulate the object instance from any file without the risk of creating multiple instances.

// Singleton class to handle object instances
class Singleton {
    private static $instance;

    public static function getInstance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    private function __construct() {
        // Constructor logic
    }

    // Additional methods and properties
}

// Usage example
$singletonInstance = Singleton::getInstance();