Polymorphism

"<?php

//Your practice code
abstract class User
{
    protected $scores = 0;
    protected $numberOfArticles = 0;

    // The abstract and concrete methods
    public function setNumberOfArticles($int)
    {
        // Cast to integer type
        $numberOfArticles = (int)$int;
        $this->numberOfArticles = $numberOfArticles;
    }

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

    abstract public function calcScore();

}

class Author extends User
{
    public function calcScore()
    {
        return $this->scores = $this->numberOfArticles * 10 + 20;
    }
}

class Editor extends User{
    public function calcScore(){
        return $this->scores = $this->numberOfArticles * 6 + 15;
    }

}

$auteur = new Author;
$auteur->setNumberOfArticles(8);
echo $auteur->calcScore();

$editor1 = new Editor();
$editor1->setNumberOfArticles(15);
echo $editor1->calcScore();"