Handshakes
In OOP PHP, “handshakes” refer to the process of ensuring that a class implements a specific interface or extends a specific class. This is done using the implements keyword for interfaces and the extends keyword for inheriting classes.
Interface
An interface in PHP is a contract that specifies a set of methods that must be implemented by any class that implements it. Interfaces are defined using the interface keyword and cannot contain any implementation code.
<?php interface Newsletter{
public function subscribe($email);
}
class CompaignMonitor implements Newsletter{
public function subscribe($email){
die('subscribinng with compaign monitor');
}
}
class Drip implements Newsletter{
public function subscribe($email){ die('subscribinng with Drip');
}}
class NewsletterSubscriptionsController{
public function store(Newsletter $newsletter){
$email = '[email protected]';
$newsletter ->subscribe($email);
}}
$controller = new NewsletterSubscriptionsController(); $controller->store(new CompaignMonitor()); I hope that you have clearly understood it.