深入理解interface

interface是PHP面向对象编程一个非常重要的概念

主要是为了作为接口而存在的一个概念

/**
 * Created by PhpStorm.
 * User: daijw
 * Date: 2017/9/11
 * Time: 下午6:20
 */
   //接口比喻为劳动协议
   interface  Logger{
    public  function  save($massage);
   }
   class FileLogger implements Logger {
       public  function  save($massage)
       {
           var_dump('log into file',$massage);
       }
   }

   class DatabaseLogger implements  Logger {
       public  function  save($massage)
       {
           var_dump('log into database',$massage);
       }
   }

   class UsersController{
       protected $logger;/**
    * UserController constructor.
    * @param $logger
    */public function __construct(Logger $logger)
   {
       $this->logger = $logger;
   }
       public function register()
       {
           $user ='davis';
           $this ->logger ->save($user);
       }
   }

   $controller = new UsersController(new DatabaseLogger());
   $controller -> register();

interface其实就是某种协议，类似于劳动合同一般的存在。