Have a look at the following code:

class A
    private $var = 17;

    public function accessOtherPrivate(A $a)
        echo $a->var;


$a = new A();
$b = new A();

The code above works just fine, you can access private properties of different object – as long as you’re the same class. PHP manual confirms the behaviour:

Members declared as private may only be accessed by the class that defines the member.

Java has the same behaviour.