how to create a custom module for overriding the core functionality in drupal with hook_user_login?

Question

I have created a module with a .info file and .module file for implementing the hook_user_login

 function custom_login_user_login(UserInterface $account) {
      $config = \Drupal::config('system.date');
      drupal_set_message("helello");
    }

//module name is custom_login i have used the xdebugger to track wheather this is working,but the function is not firing, giving me error once i have logged into the system

Answer 1

try this

 function custom_login_user_login(Drupal\user\UserInterface $account) {
      $config = \Drupal::config('system.date');
      drupal_set_message("helello");
    }