Sinter class

<?php
class Sinter
{
    private $sint;
    private $piet;
    private $ophef = [32, 101, 110, 32, 90, 119, 97, 114, 116, 101, 32, 112, 105, 101, 116, 10];

    function __construct()
    {
        $this->sint = get_class($this) . "klaas";
        $this->piet = $this->ophef();
    }

    function ophef()
    {
        $output = "";
        foreach ($this->ophef as $gelazer)
        {
            $output .= chr($gelazer);
        }
        return $output;
    }

    function sint()
    {
        return $this->sint;
    }

    function piet()
    {
        return $this->piet;
    }
}

class Piet extends Sinter
{
    function pieterbaas()
    {
        return $this->piet();
    }
}

$klaas = new Sinter("klaas");
$piet = new Piet();

echo $klaas->sint() . $piet->pieterbaas();