interface-example.php

<?php

interface Phone {
	
	public function turnOn();
	
}

class PhoneUser {
	
	private $phone;
	
	public function __construct(Phone $phone) {
		$this->phone = $phone;
		
	}
	
	public function turnOn() {

		$this->phone->turnOn();
	
	}
}

class Xiaomi implements Phone {
	
	private $xiaomi;
	
	public function turnOn() {
		echo " Xiaomi: ON";
	}
}

class Iphone implements Phone {
	
	private $xiaomi;
	
	public function turnOn() {
		echo " Iphone: ON";
	}
}

$x = new Xiaomi();
$i = new Iphone();

$xUser = new PhoneUser($x);
$xUser->turnOn();

$iUser = new PhoneUser($i);
$iUser->turnOn();