Showing how PHP handles inheritance

inheritance.php

<?php
class A {
	function __construct() {
		$this->sample_method();
	}

	private function sample_method() {
		echo "<p>I am inside the parent class 'A'</p>";
	}
}

class B extends A {
	function __construct() {
		parent::__construct();
	}

	private function sample_method() {
		echo "<p>I am inside the child class 'B'</p>";
	}
}

$b = new B; // This will use the A::sample_method() method

class C {
	function __construct() {
		$this->sample_method_c();
	}

	public function sample_method_c() {
		echo "<p>I am inside the parent class 'C'</p>";
	}
}

class D extends C {
	function __construct() {
		parent::__construct();
	}

	public function sample_method_c() {
		echo "<p>I am inside the child class 'D'</p>";
	}
}

$d = new D; // This will use the D::sample_method_c() method