class Test{
    const A = 1;
    public $b = 'two';
    private $c = test::A;

    public function __toArray(){
        return call_user_func('get_object_vars', $this);
    }
}

$my_test = new Test();
var_dump((array)$my_test);
var_dump($my_test->__toArray());

输出

array(2) {
    ["b"]=>
    string(3) "two"
    ["Testc"]=>
    int(1)
}
array(1) {
    ["b"]=>
    string(3) "two"
}

你也可以在PHP中创建一个函数来转换对象数组:

function object_to_array($object) {
    return (array) $object;
}

当你从数据库中以对象的形式获取数据时，你可能想这样做:

// Suppose 'result' is the end product from some query $query

$result = $mysqli->query($query);
$result = db_result_to_array($result);

function db_result_to_array($result)
{
    $res_array = array();

    for ($count=0; $row = $result->fetch_assoc(); $count++)
        $res_array[$count] = $row;

    return $res_array;
}

将对象类型转换为数组。

$arr =  (array) $Obj;

它会解决你的问题。

对于您的情况，如果您使用“装饰器”或“日期模型转换”模式是正确的/漂亮的。例如:

你的模型

class Car {
    /** @var int */
    private $color;

    /** @var string */
    private $model;

    /** @var string */
    private $type;

    /**
     * @return int
     */
    public function getColor(): int
    {
        return $this->color;
    }

    /**
     * @param int $color
     * @return Car
     */
    public function setColor(int $color): Car
    {
        $this->color = $color;
        return $this;
    }

    /**
     * @return string
     */
    public function getModel(): string
    {
        return $this->model;
    }

    /**
     * @param string $model
     * @return Car
     */
    public function setModel(string $model): Car
    {
        $this->model = $model;

        return $this;
    }

    /**
     * @return string
     */
    public function getType(): string
    {
        return $this->type;
    }

    /**
     * @param string $type
     * @return Car
     */
    public function setType(string $type): Car
    {
        $this->type = $type;

        return $this;
    }
}

装饰

class CarArrayDecorator
{
    /** @var Car */
    private $car;

    /**
     * CarArrayDecorator constructor.
     * @param Car $car
     */
    public function __construct(Car $car)
    {
        $this->car = $car;
    }

    /**
     * @return array
     */
    public function getArray(): array
    {
        return [
            'color' => $this->car->getColor(),
            'type' => $this->car->getType(),
            'model' => $this->car->getModel(),
        ];
    }
}

使用

$car = new Car();
$car->setType('type#');
$car->setModel('model#1');
$car->setColor(255);

$carDecorator = new CarArrayDecorator($car);
$carResponseData = $carDecorator->getArray();

这样代码就会更漂亮，更正确。

我认为使用trait来存储对象到数组的转换逻辑是一个不错的想法。举个简单的例子:

trait ArrayAwareTrait
{
    /**
     * Return list of Entity's parameters
     * @return array
     */
    public function toArray()
    {
        $props = array_flip($this->getPropertiesList());
        return array_map(
            function ($item) {
                if ($item instanceof \DateTime) {
                    return $item->format(DATE_ATOM);
                }
                return $item;
            },
            array_filter(get_object_vars($this), function ($key) use ($props) {
                return array_key_exists($key, $props);
            }, ARRAY_FILTER_USE_KEY)
        );
    }


    /**
     * @return array
     */
    protected function getPropertiesList()
    {
        if (method_exists($this, '__sleep')) {
            return $this->__sleep();
        }
        if (defined('static::PROPERTIES')) {
            return static::PROPERTIES;
        }
        return [];
    }
}

class OrderResponse
{
    use ArrayAwareTrait;

    const PROP_ORDER_ID = 'orderId';
    const PROP_TITLE = 'title';
    const PROP_QUANTITY = 'quantity';
    const PROP_BUYER_USERNAME = 'buyerUsername';
    const PROP_COST_VALUE = 'costValue';
    const PROP_ADDRESS = 'address';

    private $orderId;
    private $title;
    private $quantity;
    private $buyerUsername;
    private $costValue;
    private $address;

    /**
     * @param $orderId
     * @param $title
     * @param $quantity
     * @param $buyerUsername
     * @param $costValue
     * @param $address
     */
    public function __construct(
        $orderId,
        $title,
        $quantity,
        $buyerUsername,
        $costValue,
        $address
    ) {
        $this->orderId = $orderId;
        $this->title = $title;
        $this->quantity = $quantity;
        $this->buyerUsername = $buyerUsername;
        $this->costValue = $costValue;
        $this->address = $address;
    }

    /**
     * @inheritDoc
     */
    public function __sleep()
    {
        return [
            static::PROP_ORDER_ID,
            static::PROP_TITLE,
            static::PROP_QUANTITY,
            static::PROP_BUYER_USERNAME,
            static::PROP_COST_VALUE,
            static::PROP_ADDRESS,
        ];
    }

    /**
     * @return mixed
     */
    public function getOrderId()
    {
        return $this->orderId;
    }

    /**
     * @return mixed
     */
    public function getTitle()
    {
        return $this->title;
    }

    /**
     * @return mixed
     */
    public function getQuantity()
    {
        return $this->quantity;
    }

    /**
     * @return mixed
     */
    public function getBuyerUsername()
    {
        return $this->buyerUsername;
    }

    /**
     * @return mixed
     */
    public function getCostValue()
    {
        return $this->costValue;
    }

    /**
     * @return string
     */
    public function getAddress()
    {
        return $this->address;
    }
}

$orderResponse = new OrderResponse(...);
var_dump($orderResponse->toArray());