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How to use the .env file?
vedprad1 (913)

I have heard that using a file with the extension of .env can allow you to hide variables from other users, but I do not know exactly how to do it. Does anyone know how to do it?

Answered by CaptainAnon (147) [earned 5 cycles]
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CaptainAnon (147)

Within your .env file you can set environment variables, which is done in a KEY=VALUE format, e.g.


You should be able to use a programming language to manipulate environment variables. In python try:

import os
print(os.getenv('SECRET_KEY')) # Prints "hello_world!"
print(os.getenv('OTHER_SECRET_KEY')) # prints hello_world_again

In node.js

console.log(process.env.SECRET_KEY)) # Outputs "hello_world!"
console.log(process.env.OTHER_SECRET_KEY)) # Outputs hello_world_again

Note that quotation marks will be part of your environment variable (unlike in python or node.js where the interpreter assumes that this means your variable is a string). So H="H" means that h is assigned the value of "H" not H.

The .env file is hidden from other users, who cannot see it when they look at your repl. It is not included in forks that other users make of the repository.

RolandJLevy (1083)

Hi @vedprad1, do you know if it's possible to use the .env file in an 'HTML, CSS, JS' repl, like this one:

I'm using Firebase in this project and don't want to expose the API key in src/firebase-config.js


CoolCoderSJ (595)

@RolandJLevy You shouldn't store .env in HTML for security reasons as explained here -

RolandJLevy (1083)

Hi @CoolCoderSJ, thanks for pointing it out. Yes, you're right and I now only use .env files on the back end so they're hidden. I think I was experimenting at the time.

Can you let me know which repl you're referring to?

CoolCoderSJ (595)

@RolandJLevy Ah ok. I uh wasn’t really mentioning a repl, I just saw that you wanted env with html/js/css

RolandJLevy (1083)

Hi @CoolCoderSJ, that's cool. Thanks very much for letting me know. Happy coding!!! :)

GhostbusterJeff (1)

Is there a way to do this with Java?

windowscomputer (0)

@GhostbusterJeff yes there is a way to do it just try find the docs in docs