PHP 数组和对象--赐教

<?php 
header(‘content-type:text/html;charset=gdt8‘);

class Pre1
{
    private $name = ‘大爷‘;
    private $age = 100;
}
class Pre2 extends Pre1
{
    private $name = ‘有如神助‘;
    public $age = 111;
}
$em = (array) new Pre2 ();
echo "<pre>";
var_dump($em);
echo "</pre>";

echo "=====".$em[‘age‘] . "---<br>";
echo "=====".$em[‘Pre1name‘] . "---<br>";

foreach ($em as $key => $value)
{
    if ($key == ‘Pre1name‘)
    {
        echo ‘哒哒哒哒哒哒‘. "$value<br>";
    }
    if ($key == ‘age‘)
    {
        echo ‘嘻嘻嘻嘻嘻嘻嘻嘻‘. "$value<br>";
    }
    echo $key . ‘---‘ . $value . "<br>";
}