Question

I want to ask if it is good practice to make a class create instances of self or not, for example I have a class:

class MyClass {
    private $data = "";
    private $children = array();

    public function add() {
        $x = new MyClass();
        // do something
        // $x->some_method('');
        $this->children[] = $x;
    }

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

That way I can use some Tree functionality, but is it alright or must I do something differently?

For example creating a parent class A, with children of class B and using a multi-dimensional array in class A to store children?

Maybe someone can suggest another method doing this?

If someone had experience with this could he please provide pros and cons he noticed.

Answer 1

Is it good practice to make a class create instances of self?

it depends on why you’re doing it.

if you’re making the class create an instance of itself because you’re using it as a singleton, you can get into hot water with some people about the singleton design pattern in general.

on the other hand, I find the self-instantiation for the purpose of the factory design pattern to be exquisite. And I do recommend doing that for that particular case.