How do I use helper functions in Lumen?
问题 $credentials = app_path(); Results in: [Symfony\Component\Debug\Exception\FatalThrowableError] Call to undefined function App\LtClasses\app_path() But it's listed as a helper here: https://laravel.com/docs/5.3/helpers#method-app-path 回答1: Those are the Laravel docs, you don't have the same helpers available on Lumen, you can have a look at the helpers that the Lumen framework comes with at /vendor/laravel/lumen-framework/src/helpers.php Workarounds to achive what you need here could be app()-