In this practice, you will set up and work with environment variables in a Node.js environment.

cd into the server folder.

npm install the dependencies.

The index.js file contains a single console.log that will log the value of the NODE_ENV environment variable; however, it currently prints undefined when running:

> node index.js
> undefined

Run index.js again, but this time with the NODE_ENV environment variable set to "production" and declared within the command-line.

The app.js file contains some boilerplate code for an Express server. However, it is dependent on some environment variables. Identify the environment variables that the application is using.

Set the environment variables so that the server:

• displays the secret message "Hello from .env" at http://localhost:5000

However, instead of defining the environment variables through the command-line, use a .env file to set the environment variables that the server needs.

Create the .env file with the appropriate environment variables and values. Then, use dotenv to connect your environment variables so that the Express application runs with the configured environment variables.

Important Note: You will need to npm install the appropriate node modules to use dotenv.

You learned one way for setting and loading environment variables in a Node.js application and another way for setting and loading environment variables in an Express application.