1  

An array is not an object. So you can't cast it with a language construct. Even casting user defined objects in PHP is not possible.

数组不是对象。所以你不能用语言结构来构建它。甚至无法在PHP中构建用户定义的对象。

So you have to write your own logic. There are some fancy approaches by serialize() the object, change the class name and unserialize() it again to automate the process.

所以你必须编写自己的逻辑。 serialize()对象有一些奇特的方法,更改类名并再次反序列化()以自动化该过程。

Also you could write a cast function using reflection. But everything needs user logic.

您也可以使用反射编写强制转换函数。但一切都需要用户逻辑。

See also this post on SO: Type casting for user defined objects

另请参阅SO上的这篇文章:为用户定义的对象输入类型

So if you really like to cast objects I ended up with this function (see it in action):

因此,如果您真的想要投射对象,我最终会使用此功能(请参阅其中的操作):

function cast($to, $obj)
{
    $toLength = strlen($to);
    $serializedObj = preg_replace('/^O:\\d+:"[^"]+"/', 'O:' . $toLength . ':"' . $to . '"', serialize($obj));

    $serializedObj = preg_replace_callback('/s:(\\d+):"([^"]+)";(.+?);/', function($m) use($to, $toLength) {
        $propertyName = $m[2];
        $propertyLength = $m[1];

        if(strpos($m[2], "\0*\0") === false && ($pos = strrpos($m[2], "\0")) !== false) {
            $propertyName = "\0" . $to . "\0" . substr($m[2], $pos + 1);
            $propertyLength = ($m[1] + $toLength - $pos + 1);
        }

        return 's:' . $propertyLength . ':"' . $propertyName . '";' . $m[3] . ';';
    }, $serializedObj);

    return unserialize($serializedObj);
}

$user = array(
    'id'=> 2,
    'fname' => 'FirstName',
    'lname' => 'LastName',
    'username' => 'UserName'
);

$userObj = cast(User::class, (object)$user);

print_r($userObj);

But I would never ever use this function in production. It's just an experimental thing.

但我永远不会在生产中使用这个功能。这只是一个实验性的事情。

Update

Okay I rethought how casting is handled in Java. In Java you actually can just cast from an object to a child object of it. You can't cast from any object to any other.

好吧,我重新思考如何在Java中处理转换。在Java中,您实际上只能从一个对象转换为它的子对象。您无法从任何对象转换为任何其他对象。

So you could do this in Java:

所以你可以用Java做到这一点:

$apple = new Apple();
$macintoshApple = (MacintoshApple)$apple;

given that MacintoshApple extends Apple.

鉴于MacintoshApple扩展了Apple。

But you can't cast two unrelated objects like:

但你不能投两个不相关的对象,如:

$apple = new Apple();
$pear = (Pear)$apple;

0  

Based on your response to comment by @AbraCadaver I would look at using something like this to load DB results into an instantiated class of your choice:

根据您对@AbraCadaver评论的回应,我会考虑使用类似的东西将DB结果加载到您选择的实例化类中:

// using MySQLi
$mysqli_result = ...; // your mysqli_result object
while($class_obj = $mysqli_result->fetch_object('your_class_name')) {
    // do something
}

// using PDO
$pdo_statement = ...; // your PDOStatement object
while($class_obj = $pdo_statement->fetch_object('your_class_name')) {
    // do something
}