PHP Junior Test: Person Refactor

person.php

<?php

/**
 * A poor programmer has written the following code!
 *
 * It runs, but it's full of bad practices,
 * doesn't leverage inheritance, and abuses
 *  Object-Oriented-Programming principles.
 *
 * Refactor it like you're writing open-source
 *  code for the world to see.
 *
 * Follow any best practices you know of.
 *
 * Run this file on the command line using:
 *  $ php person.php
 *
 *  Or use a repl like https://repl.it/languages/php
 */

class Person {

    public $name;
    public $dob;
    public $nn;

    public function __construct($name, $dob, $nn){
        $this->name = $name;
        $this->dob = $dob;
        $this->nn = $nn;
    }

    public static function getLowercaseNickname($nn){ return strtolower($nn); }

    public static function n($user){ return $user->name; }
}


class Employee {

    public $name;
    public $dob;
    public $nn;
    public $pos;
    public static $curr_enum = 0;

    public function __construct($name, $dob, $nn, $pos){
        $this->name = $name;
        $this->dob = $dob;
        $this->nn = $nn;
        $this->pos = $pos;
        self::$curr_enum++;
    }

    public static function getLowercaseNickname($nn){ return strtolower($nn); }

    public static function getNumEmployees(){ return self::$curr_enum; }

    public static function n($user){ return $user->name; }

    public function pos(){ return $this->pos; }
}


$p = new Person("Corey", "1980-12-01", "The Assassin");
echo "My name is ".Person::n($p)."\n";

$e1 = new Employee("Jamal", "2017-12-01", "The Bass", "CEO");
$e2 = new Employee("Robert", "1990-10-01", "Creative Clown", 'Designer');
$e3 = new Employee("Roy", "1994-06-01", "Scumbuckler", "CTO");

echo "I've added ".Employee::getNumEmployees()." employees\n";
echo "Employee one is named ".Person::n($e1)."\n";