Class Instance Inheritance

Is it possible for a class to extend the state of its parent class? In the example provided, I was hoping for the statement to say -> "I wish 10 equals to 10" If there is a solution, I would like it to work with php 4+ Thanks ----- class foo {

    var $foo = 0;

} $foo = new foo; $foo->foo = 10; class bar extends foo {

    function bar()
    {
         echo "I wish $this->foo equals to 10";
    }

} $bar = new bar;