ส่งค่าตัวแปรไปอีกหน้ายังไง $test เขียน PHP แบบ OOP

<?php
define('host', 'localhost');
define('user', 'admin');
define('password', 'xxxxxx');
define('db', 'test');

class Load
{
	var $conn = NULL;
	function __construct($localhost='', $user='', $password='', $db="") {
		$this->conn = new mysqli($localhost, $user, $password, $db);
		$this->conn->query("SET names utf8");	
		if ($this->conn->connect_error) {
			$this->last_error = 'Cannot connect to database. ' . $conn->connect_error;
			exit;
		}
	}

	function query($str)
	{
		$result = $this->conn->query($str);
		return  $result->fetch_assoc();
	}
}
$obj = new load(host, user, password, db);
print_r($obj->query("SELECT * from customers"));
?>

class load
{
	var $conn;
	function __construct() {
	{
		$this->conn = new mysqli('localhost', 'username', 'password', 'database');
		$this->conn->set_charset($db_charset);
		if ($this->conn->connect_errno) 
		{
			echo 'MySQL not connect';
			exit;
		}
	}
	public function query($strquery)
	{
		$result = $this->conn->query($strquery);
		return $result->fetch_assoc();
	}
}

class load
{
	public function test
	{
		$test = 'test';
	}
}

require('Settings.php');
$obj = new load();
$obj -> test();
echo $test;

<?
class load
{
	public $test = '';
	
	public function test()
	{
	$this->test = 'text test';
	}
}
?>

<?
require_once('testcon.php');
$load=new load;
echo $load->test;
?>