A simple example for Observer Pattern

Observer/Observer.php

@@ -59,7 +59,7 @@ class User implements \SplSubject
     }
 
     /**
-     * 
+     *
      *
      * @return void
      */
@@ -86,4 +86,9 @@ class User implements \SplSubject
         // notify the observers, that user has been updated
         $this->notify();
     }
-}
+}
+
+$user = new User();
+$user->attach(new UserObserver());
+
+$user->notify();