How can I revise a file and see the results on docker?

General
1

I just finished creating and running my first docker container with the help of this link:

https://nodejs.org/en/docs/guides/nodejs-docker-webapp/

But when i revise my server.js file and then run the image again, I see that my changes have not been incorporated into the new container.

How do I go about doing this - that is, how do I adjust the image so that it reads my changes to my server.js file?

Thanks -