javascript - Why is process.env.NODE_ENV undefined?

Question

I'm trying to follow a tutorial on NodeJS. I don't think I missed anything but whenever I call the process.env.NODE_ENV the only value I get back is undefined. According to my research the default value should be development. How is this value dynamically set and where is it set initially?

Answer 1

process.env is a reference to your environment, so you have to set the variable there.

To set an environment variable in Windows:

SET NODE_ENV=development

on macOS / OS X or Linux:

export NODE_ENV=development