how to use env variable in laravel code example

Example 1: what is app_env in laravel

Laravel 5 uses .env file to configure your app. .env should not be committed on your repository, like github or bitbucket. On your local environment your .env will look like the following:

# .env
APP_ENV=local
For your production server, you might have the following config:

# .env
APP_ENV=production

Example 2: laravel get env variable

dd(env('APP_NAME'));

Example 3: laravel 5 use env variable in blade

Five most important commands if your Laravel is not working as expected after 
some modifications in .env or database folder or because of any other modifications. 
Here is full explanation: https://www.youtube.com/watch?v=Q1ynDMC8UGg

php artisan config:clear
php artisan cache:clear
composer dump-autoload
php artisan view:clear
php artisan route:clear

After clearup, try "echo env('URL_BUILDER')"