PHP: Make an Array of Objects Unique By Comparing a Property

If you have an indexed array of objects, and you want to remove duplicates by comparing a specific property in each object, a function like the remove_duplicate_models() one below can be used.

class Car {
    private $model;

    public function __construct( $model ) {
        $this->model = $model;
    }

    public function get_model() {
        return $this->model;
    }
}

$cars = [
    new Car('Mustang'),
    new Car('F-150'),
    new Car('Mustang'),
    new Car('Taurus'),
];

function remove_duplicate_models( $cars ) {
    $models = array_map( function( $car ) {
        return $car->get_model();
    }, $cars );

    $unique_models = array_unique( $models );

    return array_values( array_intersect_key( $cars, $unique_models ) );
}

print_r( remove_duplicate_models( $cars ) );

The result is:

Array
(
    [0] => Car Object
        (
            [model:Car:private] => Mustang
        )

    [1] => Car Object
        (
            [model:Car:private] => F-150
        )

    [2] => Car Object
        (
            [model:Car:private] => Taurus
        )

)