environment variables in node.js

environment variables in node.js

1. why to use

   • run app in any environment by modifying the env variable
     • which http port to listen which database to point to

2. when to use

   • anyplace in code that will change based on the environmemt

3. two ways to set env variable

   • command line
   • .env file
     • create a .env file in the root of the app and set the variables and values