NODE_ENV is undefined even set Up was done properly

I have a util/config.json file like below:

{
"dev": {
    "db": {
        "host": "localhost",
        "user": "root",
        "pass":"*****"
  },

"json_indentation": 4,
"database": "my-app-db-dev"

}

“prod”:{

“db”: {

“host”: “somethingt”,

“user”: “root”,

“pass”:“****”
  },

"json_indentation": 4,
"database": "my-app-db-dev"

}

}

from a util/config.js file, I have exported it to my app.js

const config = require(‘./config.json’)

const environment = process.env.NODE_ENV || ‘dev’

const defaultConfig = config.environment;

console.log(defaultConfig)  // shows undefined why?

module.exports = defaultConfig

app.js is like so:

const express = require(‘express’)

const config = require(‘./util/config’)

but it my defaultConfig shows undefined and can’t fetch the data for dev (npm run dev in app.js directory) while I have set the NODE_ENV variable like this in my package.json:

“scripts”: {

“dev”: “set NODE_ENV=dev && nodemon app.js”,

“prod”: “set NODE_ENV=prod && nodemon app.js”

}

#node-js