PHP: How to Pass child class __construct() arguments to parent::__construct()?

Question

I have a class in PHP like so:

class ParentClass {     public function __construct($arg) {         // Initialize a/some variable(s) based on $arg     } } 

It has a child class, as such:

class ChildClass extends ParentClass {     public function __construct($arg) {         // Let the parent handle construction.          parent::__construct($arg);      } } 

What if, for some reason, the ParentClass needs to change to take more than one optional argument, which I would like my Child class to provide "just in case"? Unless I re-code the ChildClass, it will only ever take the one argument to the constructor, and will only ever pass that one argument.

Is this so rare or such a bad practice that the usual case is that a ChildClass wouldn't need to be inheriting from a ParentClass that takes different arguments?

Essentially, I've seen in Python where you can pass a potentially unknown number of arguments to a function via somefunction(*args) where 'args' is an array/iterable of some kind. Does something like this exist in PHP? Or should I refactor these classes before proceeding?

Answer 1

This can be done in PHP >= 5.6 without call_user_func_array() by using the ... (splat) operator:

public function __construct() {     parent::__construct(...func_get_args()); } 

Answer 2

There is something like this in php, though a bit verbose:

$args = func_get_args(); call_user_func_array(array($this, 'parent::__construct'), $args);