<?php

error_reporting(-1);
mb_internal_encoding('utf-8');

class Worker {
	public $name;
	public $level;
	public $chief; // Принимает значения True or False
	
	
	function __construct($workers_name, $workers_level, $is_chief) {
		$name = $workers_name;
		$level = $workers_level;
		$chief = $is_chief;
	}
}
class Manager extends Worker {
	
	protected $paid = 500;
	protected $pages = 200;
	protected $coffe = 20;
	
	public function drinkCoffe($this) {
		if ($this->chief == True) {
			return ($coffe * 2);
		} else {
			return $coffe;
		}
	}
}
$Peter = new Manager('P. Stivenson', 2, True);
echo drinkCoffe($Peter);

/* Стоит создать для каждого типа работника - отдельный подкласс Worker */
?>