<?php

require "IVehicle.php";
require "Car.php";
require "Airplane.php";

$vehicles = array();
$vehicles[] = new Car();
$vehicles[] = new Airplane();

foreach($vehicles as $vehicle) { /** @var $vehicle IVehicle */
    echo $vehicle->status() . "<br>";
    $vehicle->start();
    echo $vehicle->status() . "<br>";
    $vehicle->stop();
    echo $vehicle->status() . "<br>";
    echo "<br>";
}