php - Warnings are not showing in Laravel 5.1 -

i new laravel, , want show warnings, notices , errors.

i searched lot , tried many things nothing seems work. in .env have

app_env=local app_debug=true 

in controller echo non-defined variable

echo $undefined; 

but still not showing warning or error, runs , there no entry in laravel.log file.

check app.php in config/app.php

'debug' => env('app_debug', true) 

is true or false ?