If you were programming in Python or many other languages you could download documentation and have a local copy.

In both Python and Java doing a mini-project I frequently challenge myself to only use the standard library. It's good for practicing HackerRank-rank style programming (the fun of single-file Java)

When I am waiting for builds I sometimes hack on this

https://github.com/paulhoule/pidove

because I don't really like the Streams API and want to perfect my mastery of generics and internal DSLs.

Now that I think of it, standard-library only for node seems like a good challenge for me because I code a lot of front-end Javascript but just barely know the node API.

I've also hacked on things that are data-science and A.I. related on the bus where I've very deliberately set up a Jupyter environment with everything I need before the trip.

Downloading docs is a good Idea. Will check if I can get all the docs for all the various packages. Basically that is not that important, because I already know them pretty well. Actually thought to do some stuff with cython, but guess for that I really need stack overflow to come fast forward.

Doc can be downloaded with Zeal

Thanks a lot for the hint. That is very helpful!

Why not the way we did it in 1995 most of the time? Out of the head and big fat book.

Guess depends on the problem, would love to do it this way. Kind of difficult if you are working with new frameworks.

wget -r 'framework.docs'

Get as much of the documentation you can find downloaded.