OOP basics

index.php

<?php

require 'Person.php';

$pesho = new Person;
$pesho->setHairColor('orange');
$pesho->printHairColor();

$ivan = new Person;
$ivan->setHairColor('black');
$ivan->printHairColor();

Person.php

<?php

class Person
{
    protected $hairColor;
    protected $eyeColor;

    public function run()
    {
        echo 'running';
    }

    public function setHairColor($color)
    {
        $this->hairColor = $color;
    }

    public function printHairColor()
    {
        echo $this->hairColor;
    }
}