Just typecast it

$array = (array) $yourObject;

From Arrays:

If an object is converted to an array, the result is an array whose elements are the object's properties. The keys are the member variable names, with a few notable exceptions: integer properties are unaccessible; private variables have the class name prepended to the variable name; protected variables have a '*' prepended to the variable name. These prepended values have null bytes on either side.

Example: Simple Object

$object = new StdClass;
$object->foo = 1;
$object->bar = 2;

var_dump( (array) $object );

Output:

array(2) {
  'foo' => int(1)
  'bar' => int(2)
}

Example: Complex Object

class Foo
{
    private $foo;
    protected $bar;
    public $baz;

    public function __construct()
    {
        $this->foo = 1;
        $this->bar = 2;
        $this->baz = new StdClass;
    }
}

var_dump( (array) new Foo );

Output (with \0s edited in for clarity):

array(3) {
  '\0Foo\0foo' => int(1)
  '\0*\0bar' => int(2)
  'baz' => class stdClass#2 (0) {}
}

Output with var_export instead of var_dump:

array (
  '' . "\0" . 'Foo' . "\0" . 'foo' => 1,
  '' . "\0" . '*' . "\0" . 'bar' => 2,
  'baz' =>
  stdClass::__set_state(array(
  )),
)

To know more about php built-in class stdclass. You can read this documentation

Typecasting this way will not do deep casting of the object graph and you need to apply the null bytes (as explained in the manual quote) to access any non-public attributes. So this works best when casting StdClass objects or objects with only public properties. For quick and dirty (what you asked for) it's fine.

Also see this in-depth blog post:

• Fast PHP Object to Array conversion

In the simplest case, it's probably sufficient to "cast" the array as an object:

$object = (object) $array;

Another option would be to instantiate a standard class as a variable, and loop through your array while re-assigning the values:

$object = new stdClass();
foreach ($array as $key => $value)
{
    $object->$key = $value;
}

As Edson Medina pointed out, a really clean solution is to use the built-in json_ functions:

$object = json_decode(json_encode($array), FALSE);

This also (recursively) converts all of your sub arrays into objects, which you may or may not want. Unfortunately it has a 2-3x performance hit over the looping approach.

Warning! (thanks to Ultra for the comment):

json_decode on different enviroments converts UTF-8 data in different ways. I end up getting on of values '240.00' locally and '240' on production - massive dissaster. Morover if conversion fails string get's returned as NULL

Single-dimensional arrays

For converting single-dimension arrays, you can cast using (array) or there's get_object_vars, which Benoit mentioned in his answer.

// Cast to an array
$array = (array) $object;

// get_object_vars
$array = get_object_vars($object);

They work slightly different from each other. For example, get_object_vars will return an array with only publicly accessible properties unless it is called from within the scope of the object you're passing (ie in a member function of the object). (array), on the other hand, will cast to an array with all public, private and protected members intact on the array, though all public now, of course.

Multi-dimensional arrays

A somewhat dirty method is to use PHP >= 5.2's native JSON functions to encode to JSON and then decode back to an array. This will not include private and protected members, however, and is not suitable for objects that contain data that cannot be JSON encoded (such as binary data).

// The second parameter of json_decode forces parsing into an associative array
$array = json_decode(json_encode($object), true);

Alternatively, the following function will convert from an object to an array including private and protected members, taken from here and modified to use casting:

function objectToArray ($object) {
    if(!is_object($object) && !is_array($object))
        return $object;

    return array_map('objectToArray', (array) $object);
}

No

There is no __toArray magic method in PHP. An enhancement proposal has been rejected in 2006 with the following answer:

[2006-08-20 11:12 UTC] [email protected]

Why not simply have a method asArray() maybe even as par of an interface:

interface ArrayConversion { function asArray(); }

See, we have __toString as it is supported in language constructs like echo, print and other internal functions. But we decided against an autoconversion for arrays already. So itwill never be supported in any language construct. That said there is no needed for this and nothing you would win against the above interface. In fact you would make it php more complex because you'd add just one more magic feature.

It is thus very unlikely that it will be implemented in any future release (which is a pity, if you ask me).

From the manual:

If an object is converted to an array, the result is an array whose elements are the object's properties. The keys are the member variable names, with a few notable exceptions: integer properties are unaccessible; private variables have the class name prepended to the variable name; protected variables have a '*' prepended to the variable name. These prepended values have null bytes on either side. This can result in some unexpected behaviour:

You can therefore work around the issue like this:

$temp = (array)(new Teste('foo','bar'));
$array = array();
foreach ($temp as $k => $v) {
  $k = preg_match('/^\x00(?:.*?)\x00(.+)/', $k, $matches) ? $matches[1] : $k;
  $array[$k] = $v;
}
var_dump($array);

It does seem odd that there is no way to control/disable this behaviour, since there is no risk of collisions.