<?php
    /**
     * Define MyClass
     */
    class MyClass
    {
        public $public = 'Public';
        protected $protected = 'Protected';
        private $private = 'Private';

        function printHello()
        {
            echo $this->public;
            echo $this->protected;
            echo $this->private;
        }
    }

    $obj = new MyClass();
    echo $obj->public; // Works(
        echo $obj->protected; // Fatal error
        echo $obj->private; // Fatal error
        $obj->printHello(); // Shows Public, Protected, and Private

    /**
     * Define MyClass2
     */
    class MyClass2 extends MyClass
    {
        // We can redeclare the public and protected properties, but not private
        public $public = 'Public2';
        public $protected = 'Protected2';

        function printHello()
        {
            echo $this->public;
            echo $this->protected;
            echo $this->private;
        }
    }

    $obj2 = new MyClass2();
    echo $obj2->public; // Works
    echo $obj2->protected; // Fatal Error
    echo $obj2->private; // Undefined
    $obj2->printHello(); // Shows Public2, Protected2, Undefined
?>