How do I Use Inner Classes in PHP?

Question

I'm from a Java background, and I want to use an inner class in php. Every time I put the inner class though, I get a syntax error. Is this possible with PHP? Also, how do I reference the outer class? Do I get access to ALL its data members?

<?php  class OuterClass {     var $x = 15;     function __construct() {      }      class InnerClass {                  // error when InnerClass is static         function __construct() {        // error when InnerClass is static             echo $x;         }     } }  ?> 

This is used for a MoveClass (as in make a move) of a specific card game. I think it'd be good design to put these classes together because they don't make sense apart. Also, the MoveClass needs to know about some data members of the Game class. Why not make it a function? It's simply too big.

Edit:

What about nested classes? From what I understand, those have to be static? O_o

Answer 1

PHP does not allow for inner classes. Should you wish to access all of the data members from the parent class, I would suggest you employ Inheritance.

A possible alternative:

class OuterClass {     var $x = 15;     function __construct() {      } } class ChildClass extends OuterClass {     function __construct() {         parent::__construct();     } } 

You can envoke a method form the parent class by referring to the class itself; In PHP you can do this with the parent keyword. So, to refer to a method in the context of a class rather than an object we use :: as opposed to ->.

Answer 2

in PHP 5.4 or later, you can use PHP Traits which are designed more for multiple inheritance, but may suit your needs. From the PHP Documentation:

A Trait is similar to a class, but only intended to group functionality in a fine-grained and consistent way. It is not possible to instantiate a Trait on its own. It is an addition to traditional inheritance and enables horizontal composition of behavior; that is, the application of class members without requiring inheritance.

http://php.net/manual/en/language.oop5.traits.php