class.php

<?php

class PHPer {
	public $name = '???';
	public $PHP力 = '???';
	public function PHPを教える(PHPer $教え子) {
		$教え子->PHP力 = '強い';
	}
}

$hirosan = new PHPer();
$hirosan->name = 'hiro';
$hirosan->PHP力 = '強い';

$僕 = new PHPer();
$僕->name = 'suin';
$僕->PHP力 = '初心者くらい';

echo '<pre>';
var_dump($僕);

$hirosan->PHPを教える($僕);

var_dump($僕);