Creating anonymous objects in php

Question

"Anonymous" is not the correct terminology when talking about objects. It would be better to say "object of anonymous type", but this does not apply to PHP.

All objects in PHP have a class. The "default" class is stdClass, and you can create objects of it this way:

$obj = new stdClass;
$obj->aProperty = 'value';

You can also take advantage of casting an array to an object for a more convenient syntax:

$obj = (object)array('aProperty' => 'value');
print_r($obj);

However, be advised that casting an array to an object is likely to yield "interesting" results for those array keys that are not valid PHP variable names -- for example, here's an answer of mine that shows what happens when keys begin with digits.

It has been some years, but I think I need to keep the information up to date!

Since PHP 7 it has been possible to create anonymous classes, so you're able to do things like this:

<?php

    class Foo {}
    $child = new class extends Foo {};

    var_dump($child instanceof Foo); // true

?>

You can read more about this in the manual

But I don't know how similar it is implemented to JavaScript, so there may be a few differences between anonymous classes in JavaScript and PHP.

Up until recently this is how I created objects on the fly.

$someObj = json_decode("{}");

Then:

$someObj->someProperty = someValue;

But now I go with:

$someObj = (object)[];

Then like before:

$someObj->someProperty = someValue;

Of course if you already know the properties and values you can set them inside as has been mentioned:

$someObj = (object)['prop1' => 'value1','prop2' => 'value2'];

NB: I don't know which versions of PHP this works on so you would need to be mindful of that. But I think the first approach (which is also short if there are no properties to set at construction) should work for all versions that have json_encode/json_decode

Yes, it is possible! Using this simple PHP Anonymous Object class. How it works:

// define by passing in constructor
$anonim_obj = new AnObj(array(
    "foo" => function() { echo "foo"; }, 
    "bar" => function($bar) { echo $bar; } 
));

$anonim_obj->foo(); // prints "foo"
$anonim_obj->bar("hello, world"); // prints "hello, world"

// define at runtime
$anonim_obj->zoo = function() { echo "zoo"; };
$anonim_obj->zoo(); // prints "zoo"

// mimic self 
$anonim_obj->prop = "abc";
$anonim_obj->propMethod = function() use($anonim_obj) {
    echo $anonim_obj->prop; 
};
$anonim_obj->propMethod(); // prints "abc"

Of course this object is an instance of AnObj class, so it is not really anonymous, but it makes possible to define methods on the fly, like JavaScript do.

Convert array to object (but this is not recursive to sub-childs):

$obj = (object)  ['myProp' => 'myVal'];