Organize and relate class in PHP

Question

Well, I am trying to adapt my old code to a more object oriented model but I find difficulties in doing it. The structure of my classes would look like this:

// config.php
class Config {
    const Setting1 = 'value';
    const Setting2 = 'value';
}

// main.php
include 'config.php'

class Main {
    var $Config;
    var $Info;
    var $Db;

    function _construct() {
        $this->Config = &new Config;
        $this->Info = &new Info;
        $this->Db = &new Db($this);
    }
}

class Info {
    function getSetting($a, $Config) {
        if ($a>0) return $Config::Setting1;
        return $Config::Setting2;
    }
}

class Db {
    function _construct($Main) {
        $Setting1 = $Main->Config::Setting1;
    }
}

// index.php
$Main = new Main;
echo $Main->Info->getSetting(1, $Main->Config);

So, as you see, there are incorrect things in this code. What I want is to have everything inside the Main class, create the $Main object and from there access any other object. Db will need a constant from Config yet I don't want to create a new Config inside Db but use the one from Main. The same happens with Info.

Answer 1

The problem should be fixed with this:

// config.php
class Config {
    public static $Setting1 = 'value';
    public static $Setting2 = 'value';
}

// main.php
include('config.php');

class Main {
    private $Info = null;
    private $Db = null;

    public function _construct() {
        $this->Info = new Info();
        $this->Db = new Db();
    }

    public function getSetting($a) {
        return $this->Info->getSetting($a);
    }
}

class Info {
    public function getSetting($a) {
        if ($a>0) return Config::$Setting1;
        return Config::$Setting2;
    }
}

class Db {
    public function _construct() {
        $Setting1 = Config::$Setting1;
    }
}

// index.php
$Main = new Main();
echo $Main->getSetting(1);