如何使用PHP7的匿名类实现更加灵活和可扩展的对象封装？

$object = new class {
    public function sayHello() {
        echo "Hello, World!";
    }
};

$object->sayHello(); // 输出：Hello, World!

class ParentClass {
    public function sayHello() {
        echo "Hello, Parent!";
    }
}

$object = new class extends ParentClass {
    public function sayHello() {
        parent::sayHello();
        echo "Hello, Child!";
    }
};

$object->sayHello(); // 输出：Hello, Parent! Hello, Child!

interface Greeting {
    public function sayHello();
}

$object = new class implements Greeting {
    public function sayHello() {
        echo "Hello, World!";
    }
};

$object->sayHello(); // 输出：Hello, World!

class ObjectFactory {
    public function createObject($condition) {
        if ($condition === 'A') {
            return new class {
                public function sayHello() {
                    echo "Hello, Object A!";
                }
            };
        } else if ($condition === 'B') {
            return new class {
                public function sayHello() {
                    echo "Hello, Object B!";
                }
            };
        }
        // 其他条件下的对象创建逻辑...
    }
}

$factory = new ObjectFactory();
$objectA = $factory->createObject('A');
$objectA->sayHello(); // 输出：Hello, Object A!

$objectB = $factory->createObject('B');
$objectB->sayHello(); // 输出：Hello, Object B!

class ObjectContainer {
    private $objects = [];
    
    public function addObject($condition) {
        if (!isset($this->objects[$condition])) {
            $this->objects[$condition] = new class($condition) {
                private $condition;
                
                public function __construct($condition) {
                    $this->condition = $condition;
                }
                
                public function sayHello() {
                    echo "Hello, Object with condition: {$this->condition}!";
                }
            };
        }
    }
    
    public function getObject($condition) {
        if (isset($this->objects[$condition])) {
            return $this->objects[$condition];
        }
    }
}

$container = new ObjectContainer();
$container->addObject('A');
$objectA = $container->getObject('A');
$objectA->sayHello(); // 输出：Hello, Object with condition: A!

$container->addObject('B');
$objectB = $container->getObject('B');
$objectB->sayHello(); // 输出：Hello, Object with condition: B!