UsersController_with_Interface.php

<?php
interface Logger 
{
    public function execute($message);
}
class LogToDatabase implements Logger 
{
    public function execute($message){
        var_dump('log the message to a database :'.$message);
    }
}
class LogToFile implements Logger 
{
    public function execute($message) 
    {
        var_dump('log the message to a file :'.$message);
    }
}
class UsersController 
{
    protected $logger;
    
    public function __construct(Logger $logger) 
    {
        $this->logger = $logger;
    }
    
    public function show() 
    {
        $user = 'nahid';
        $this->logger->execute($user);
    }
}

$controller = new UsersController(new LogToDatabase);
$controller->show();