PHP. Is it possible to use array_column with an array of objects

Is it possible to pass in array_column an array of objects?
I have implemented ArrayAccess interface, but it has no effect.
Should I implement another one?

class Foo implements ArrayAccess {

	public $Id, $Title;

	public function offsetExists($offset)
	{
		return isset($this->{$offset});
	}    

	public function offsetGet($offset)
	{
		return $this->{$offset};
	}

	public function offsetSet($offset, $value)
	{
		$this->{$offset} = $value;
	}

	public function offsetUnset($offset)
	{
		unset($this->{$offset});
	}
}
    
$object = new \Foo();
$object->Id = 1;
$object->Title = 'Test';

$records = array(
	$object, 
    array(
        'Id' => 2,
        'Title' => 'John'
    )
);
   
var_dump(array_column($records, 'Title')); // array (size=1) 0 => string 'John' (length=4)

PHP 5

array_column doesn't work with an array of objects. Use array_map instead:

$titles = array_map(function($e) {
    return is_object($e) ? $e->Title : $e['Title'];
}, $records);

PHP 7

array_column()

> The function now supports an array of objects as well as > two-dimensional arrays. Only public properties are considered, and > objects that make use of __get() for dynamic properties must also > implement __isset().

See https://github.com/php/php-src/blob/PHP-7.0.0/UPGRADING#L629 - Thanks to Bell for the hint!

> Is it possible to pass in array_column an array of objects?

PHP 7

Yes, see http://php.net/manual/en/function.array-column.php

PHP 5 >= 5.5.0

In PHP 5 array_column does not work with an array of objects. You can try with:

// object 1
$a = new stdClass();
$a->my_string = 'ciao';
$a->my_number = 10;

// object 2
$b = new stdClass();
$b->my_string = 'ciao b';
$b->my_number = 100;

// array of objects
$arr_o = array($a,$b);

// using array_column with an array of objects
$result = array_column(array_map(function($o){return (array)$o;},$arr_o),'my_string');

PS: for clarity I prefer to not use array_column and use array_map with an anonymous function

$result = array_map(function($o){ return $o->my_string; }, $arr_o);

or a simple foreach

$result = array();
foreach($arr_o as $o) {
    $result[] = $o->my_string;
}

Here is a function that will work on both php7 and php5

function array_column_portable($array, $key) {
    return array_map(function($e) use ($key) {
        return is_object($e) ? $e->$key : $e[$key];
    }, $array);
}

You can then use it as you use array_column in php7

Possible solution is prepare that array of objects:

$objectsList = [];

foreach ($objs as $obj) {        
    $objectsList[] = (array)$obj;
}

$propList = array_column($objectsList, 'prop');

While it's not possible to use array_column on child-objects, you can cast them to arrays. This is of course not the way to go, but it's a way.

Using array_map/get_object_vars (doesn't not work in your case, due the containing array)

array_column(array_map('get_object_vars', $thingy), 'property');

Using json_decode/json_encode

array_column(json_decode(json_encode($thingy), true), 'property');

https://eval.in/597950

Note: Using json brings not the same result as using a true recursive function. You’ll lose protected and private properties of the object. But in some situations its fine.

function object_to_array($object) {
  if (is_object($object)) $object = get_object_vars($object);
  return is_array($object) ? array_map(__FUNCTION__, $object) : $object;
}