create react app use env variables code example

Example 1: react environment variables

// Place a filer called .env at the doc root of your project
/*
my-react-app/ 
 |-node-modules/
 |-src/
 |-public/
 |-.env
 |-gitignore
 |-package.json
 |-package.lock.json.
 |-README.md
*/
// Edit the .env file and create your cusotm Environment Variables
// DO NOT USE SINGLE OR DOUBLE QUOTES!

REACT_APP_CLIENT_ID=jfjffffaddfeettgydgdffv
REACT_APP_KEY=aaddddawrfffvvvvssaa

// They will be READ-ONLY from your JS file, you can print them
// or assign them to other variables

console.log(process.env.REACT_APP_CLIENT_ID);
console.log(process.env.REACT_APP_KEY);

var id = process.env.REACT_APP_CLIENT_ID;
var key = process.env.REACT_APP_KEY;

Example 2: create-react-app enviroment variables

process.env.NODE_ENV gives you either "development" or "production" or "test"
When you run npm start it is equal to develpment
When you run npm run build it is equal to production
When you run npm test it is equal to test