How to start node app with development flag?

Question

At top of my app.js file I put

NODE_ENV=\'development\';

but I get error that NODE_ENV is not defined. But in the nodejs documentation is says

Answer 1

If you want to set an environment variable in your js file you should do it this way:

process.env.NODE_ENV = 'development';

Alternatively you can set the variable in your shell and run your application:

$ NODE_ENV="development" node ./app.js

or export the variable and run your application:

$ export NODE_ENV="development"
$ node ./app.js

On Windows:

$ set NODE_ENV="development"
$ node app.js