Converting PHP Objects to Arrays to read private members

Since long time ago, PHP supports the very interesting yet feature of object to array conversion through simple casting via (array):

<?php

class Foo {
    public $bar = 'barValue';
}

var_dump((array) new Foo());

You can see a running example at http://3v4l.org/FC3WT

This allows us to apply fast conversions when serializing data in JSON or XML for example.

Weirdly, it allows us to also retrieve private and protected properties:

<?php

class Foo {
    public $bar = 'barValue';
    protected $baz = 'bazValue';
    private $tab = 'tabValue';
}

var_dump((array) new Foo());

A live example is at http://3v4l.org/sGnfO

The keys for private and protected values are quite strange though:

• For protected values, the key is "\0*\0$propertyName"
• For private values, the key is "\0$classFQCN\0$propertyName"

You can see a quick demonstration at http://3v4l.org/6o7Ac

While this may not make sense to many people, this is how actually PHP represents objects internally, and it is thought this way to avoid any collisions in object serialization.

Use with caution - clearly violates OOP principles

I wrote more extensively on the topic at http://ocramius.github.io/blog/fast-php-object-to-array-conversion/