how to add environment variable for node js and npm code example

Example 1: node start with environment variables

#Bash

NODE_ENV=production && OTHER_ENV=foo && node ./index.js
#or if you have your npm scripts set
NODE_ENV=production && OTHER_ENV=foo && npm start

#Powershell

$env:NODE_ENV="production"; $env:OTHER_ENV="foo"; node .\index.js
#or if you have your npm scripts set
$env:NODE_ENV="production"; $env:OTHER_ENV="foo"; npm run build

#CMD

set NODE_ENV=production && set OTHER_ENV=foo && node .\index.js
#or if you have your npm scripts set
set NODE_ENV=production && set OTHER_ENV=foo && npm run build

Example 2: node how to set environment variable

// get an environment variableexport const token = process.env['API_TOKEN'];// set an environment variable at runtimeprocess.env['RANDOM_ID'] = Math.random();