访问类构造函数和函数内的数组

Question

What's the best practice to access config from functions and classes? The below code is working, but it seems the wrong way.

How I could improve this? I'm free to change every part.

config.php

return [
    'ENVIRONMENT'  => 'development',
    'DB_HOST'  => '127.0.0.1'
];

index.php

$config = require 'config.php';
$config = (object) $config;
...
$router->get('/test/user/create', function() {
    global $config;
    $login = new \Demo\Login($config);
    ...
    _view('main');
});
...
function _view($page){
    global $config;

    header('Content-Type: text/html; charset=utf-8');
    require_once('../view/'.$page.'.php');
}

Login.php

public $config = '';

public function __construct($config) {
    $this->config = $config;
    echo $this->config->ENVIRONMENT;
}