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in the .env file I set some variables //file .env


But when you call it in a js file, I get an undefined value //file index.js


and when executing node index.js


Can you explain me why this happens, Thanks.

If you include the dotenv dependancy you won't have this problem

Then simply add at the top of your script

import dotenv from 'dotenv';

(if you have es6 via babel / createreactapp etc)



How To Read and Set Environmental and Shell Variables on a , In Linux systems, environmental and shell variables are used to like we did by calling the bash command from the terminal, a non-login shell  By default it is taking.env from the project working directory, but if you have created the.env file with different name than you need to specify the path. After that you can console your env variable inside the code anywhere. answered Dec 29 '18 at 19:01 radhey shyam radhey shyam

When you create .env file, for that time it is just a file like other js or text files, to use it we need to use dotenv npm package.


We need to use it on the top of our initial node project file.

i.e index.js

Syntax For ES6/Type Script (With babel transpilation)

import dotenv from 'dotenv';


dotenv.config({path: `<path of .evn file>`});

Syntax for ES5 node js environment



require('dotenv').config({path: <path of .env file>});

By default it is taking .env from the project working directory, but if you have created the .env file with different name than you need to specify the path.

After that you can console your env variable inside the code anywhere.

Environment Variables, Setting Environment Variables. This section teaches you how to set environment variables, check if a particular environment variable exists, and display a list of set  Please enter environment variable name: datatype Please enter environment variable value: CSV datatype=CSV environment variable has been set. If the environment variable already exists, it will be overwritten by the new value. The environment variable will be set only for the current session of the Python interpreter. If you want to change to be permanent, then you will have to edit the user profile file in the Python program.

Import dotenv npm module.

const dotenv = require('dotenv').config();

How To Set Environment Variables, Learn why environment variables are useful and how to set them on me an email to: or contact me on Twitter @dkundel. Through PowerShell To read an Environment Variable in PowerShell, simply use the prefix “ $env: “, follow by the name of the variable. What’s better is that this prefix env is actually a drive so you can use a simple cmdlet such as dir to find and list all Environment Variables at once.

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Environment variable, This procedure gives the calling program control over the environment of the called program. In Unix and Unix-like systems, the names of environment variables  To set persistent environment variables at the command line, we will use setx.exe. It became part of Windows as of Vista/Windows Server 2008. Prior to that, it was part of the Windows Resource Kit. If you need the Windows Resource Kit, see Resources at the bottom of the page.

How to Set and List Environment Variables in Linux, In Linux and Unix based systems environment variables are a set of dynamic named values, stored within the system that are used by  Create React App supports custom environment variables without the need to install any other packages. There are two methods of adding environment variables: Through the shell (temporary, lasts as