Javascript-like objects in PHP?

Question

It's pretty handy in JS to create objects like this:

test = { foo : { bar : "hello world" }, bar2 : "hello world 2" }

and then use them like:

test.foo.bar
test.bar2

Is there anything like this in PHP without declaring classes?

Answer 1

It's called associative arrays.

Example (note: the indentation is for layout purposes):

$test = array(
  'foo' => array(
     'bar' => 'hello world'
   ),
  'bar2' => 'hello world 2'
);
$test['foo']['bar'];
$test['bar2'];

This is equivalent to the following Javascript code:

var test = {
  'foo': {
    'bar': 'hello world',
  },
  'bar2': 'hello world 2'
};

As an alternative, you can use the pre-declared StdClass.

$test = new StdClass;
$test->foo = new StdClass;
$test->foo->bar = 'hello world';
$test->bar2 = 'hello world 2';

which would be written in JavaScript as:

var test = new Object;
test.foo = new Object;
test.foo.bar = 'hello world';
test.bar2 = 'hello world 2';

(note: new Object is the same as {} in Javascript)

Answer 2

stdClass allows you to create (essentially) typeless objects. For example:

$object = (object) array(
    'name' => 'Trevor',
    'age' => 42
);

As shown here, the fastest way to create a stdClass object is to cast an associative array. For multiple levels, you just do the same thing again inside like this:

$object = (object) array(
    'name' => 'Trevor',
    'age' => '42',
    'car' => (object) array(
        'make' => 'Mini Cooper',
        'model' => 'S',
        'year' => 2010
     )
);

Another method is to convert the associative array to an object afterwards with a recursive function. Here's an example.

function toObject(array $array) {
    $array = (object) $array;
    foreach ($array as &$value)
        if (is_array($value))
            $value = toObject($value);

    return $array;
}
// usage:
$array = // some big hierarchical associative array...
$array = toObject($array);

This is useful when you're not the one making the associative array.

Unfortunately, even though PHP 5.3 supports anonymous methods, you cannot put an anonymous method into a stdClass (though you can put one into an associative array). But this isn't too bad anyway; if you want functionality in it, you really should create a class instead.

Answer 3

You can use a StdClass object or an ArrayObject which are included in php (though the latter requires that you have SPL installed). Though unless you need to access the values specifically with the -> operator its more efficient to just use an associative array instead.