PHP arrays and objects - Comments

Turn an array of objects, originally privatized property can not be used to compare and $ em [ ''] so that the output , but the output loop is no problem, strange, people know please leave a message! !

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

class Pre1
{
    private $name = '大爷';
    private $age = 100;
}
class Pre2 extends Pre1
{
    Private  $ name = 'as helpful' ;
     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 'da da da da da da'. " $ value <br>" ;
    }
    if ($key == 'age')
    {
        echo . 'hee hee hee hee hee hee hee' " $ value <br>" ;
    }
    echo $key . '---' . $value . "<br>";
}