How to Use Environment Variables in Node.js Applications?

Using environment variables in Node.js applications is a best practice for managing configuration settings, such as API keys and database credentials. Here's how to implement them:

• First, create a file named .env in your project root. This file will hold your environment variables in the format KEY=VALUE.

• Next, install the dotenv package by running npm install dotenv.

• In your main application file (e.g., app.js or server.js), require and configure dotenv as follows:

  require('dotenv').config();

• Now, you can access your environment variables using process.env.KEY. For example:

  const dbPassword = process.env.DB_PASSWORD;

Make sure to add .env to your .gitignore file to prevent it from being tracked in version control.