Showing object private properties - php

Question

This is homework. I have created 2 classes, Objecte and Ordinador. It is mandatory that Ordinador properties are private, and $preu in Objecte too.
<?php
class Objecte
{
var $model;
private $preu;
public function __construct($model,$preu)
{
$this->model=$model;
$this->preu=$preu;
}
}
?>
This is Ordinador:
<?php
include('classe_objecte.php');
class Ordinador extends Objecte
{
private $disc_dur;
private $ram;
public function Ordinador($model,$preu,$disc_dur,$ram)
{
parent::__construct($model,$preu);
$this->disc_dur=$disc_dur;
$this->ram=$ram;
}
}
?>
So I have stored some objects I've created. They're stored in a SESSION array. So now I must show the values, but as they're private in the classes, I get this errors:
Notice: Undefined property: Ordinador::$preu
Fatal error: Cannot access private property Ordinador::$disc_dur
Any suggestions how to access to it?.

Answer 1

You have to create a public function that calls to the private var
public function getPreu(){
return $this->preu;
}

Answer 2

instead of:
parent::__construct($model,$preu);
try:
$this->__construct($model,$preu);

Answer 3

In this case I'm storing the objects like this:
$index=$_SESSION['numOrdinadorsO'];
$_SESSION['objetos_ordinador'][$index]=inserirOrdinadorO();
And funtion inserirOrdinadorO looks like this:
function inserirOrdinadorO()
{
$_SESSION['ordinadorsO']=array('model_ordinadors'=>$_POST['model_ordinadors'],'preu_ordinadors'=>$_POST['preu_ordinadors'],'tamany'=>$_POST['tamany'],'ram'=>$_POST['ram']);
$model=$_SESSION['ordinadorsO']['model_ordinadors'];
$preu=$_SESSION['ordinadorsO']['preu_ordinadors'];
$disc_dur=$_SESSION['ordinadorsO']['tamany'];
$ram=$_SESSION['ordinadorsO']['ram'];
$ord_tmp = new Ordinador($model,$preu,$disc_dur,$ram);
$_SESSION['numOrdinadorsO']+=1;
echo "Objecte Ordinador inserit.</br>";
return $ord_tmp;
}
Not sure how to implement the solution Yair gave me:
$obj = new Objecte('modele','preu'); And then echo $obj->getPreu();