i think that is a bug but i'm not sure if is a php behavior

<?php
class Father{private $x = 'FATHER';
public function a(){echo $this->x;}
}

class Son extends Father{private $x = 'SON';
// try to decomment this:
//public function a(){echo $this->x;}
}

$son_instance = new Son;
$son_instance->a();

?>

.........
class Son extends Father{private $x = 'SON';
// try to decomment this:
//public function a(){echo $this->x;}
}
.............

I know if I override method a() in the child - everything will be ok, but it's not necessary to override method a(), because method a() is inherited form father class and it's public.

p.s. if it's a bug, then it's php behavior.

sure i know i don't need to override the method with the same one in the new class to fix this problem

in the parent class the field is private... so theoretically i can not access the member in the derived class

class A
{
	private $a = "a";
}
class B extends A
{
        private $a = "b"; // is this an error?
}

it probably is, and maybe php should throw an error

in fact if you use protected instead of private it works as expected
but the "private" issue should be clarified, i think

* i'm sorry for the second post

as for your code:

class A
{
	private $a = "a";
}
class B extends A
{
        private $a = "b"; // is this an error?
}

i think every class has own private member, so there is no error.
--------------------------------------------------------------------
Ok, I got you.
I hope that this issue will be clarified.
Thank you for discussion.

You are calling show_private_member(). That method belongs to Father and therefore has access to Father's private elements. The method has no access to other class's private elements. Are you looking for protected elements?

1) Answer for your question "Are you looking for protected elements?" is "Bug #52245 Private member of parent class accessible from child class."

2) Why you say that show_private_member() belongs to Parent class, if it is inherited by its Child? In addition, I redefined the private member in Child class - then, according to the paradigm of OOP polimoryizm, the method should return a value of Child private member, otherwise all you have said is contrary to OOP, in particular, to polymorphism.

Could you please answer to my questions?

Private enforces encapsulation, a key element of OOP. The current behavior ensures you can extend the class without an effect on  show_private_member() and whatever happens in there. With your change extending the class can hae an effect (by accident) on the method.

.