<?PHP
class Main {
  public $VARs = array();
}

$main = new Main;

$main->vars['key'] = 'value';

class Extended extends Main { }

$other = new Extended;

var_dump($other->vars);

?>

<?PHP
class Extended extends Main {
  function __construct ($main) {
    foreach ($main as $k => $v) {
      $this->$k = $v;
    }
  }
}
?>

编辑：使用控制反转(IoC)和依赖注入(DI)可以更好地解决这个问题.如果您使用自己的框架或没有依赖注入容器的框架,请尝试 League/Container

下面的回答是愚蠢答案的历史.

我想的正确方法.

<?PHP
class Config {
    PRotected $_vars = array();

    protected static $_instance;

    private function __construct() {}

    public static function getInstance()
    {
        if (!isset(self::$_instance)) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }

    public function &amp;__get($name) {
        return $this->_vars[$name];
    }

    public function __set ($name,$value) {
        $this->_vars[$name] = $value;
    }
}

$config = Config::getInstance();
$config->db = array('localhost','root','');
$config->templates = array(
    'main' => 'main','news' => 'news_list'
);

class DB {
    public $db;

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

    public function connect()
    {
        MysqL_connect($this->db[0],$this->db[1],$this->db[2]);
    }
}

$config = Config::getInstance();
$db = new DB($config->db);
$db->connect();

class Templates {
    public $templates;

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

    public function load ($where) {
        return $this->templates[$where];
    }
}

$config = Config::getInstance();
$templates = new Templates($config->templates);
echo $templates->load('main') . "\n";