I never bought a programming book in all of my professional career, since the 90s. The only ones I did buy were the K&R C book and the Pascal book at university. They were mandatory readings and basically the only way to learn those languages. Perl? Man pages and online. Tcl? Same thing. When I started working, my company had the whole series of the X11 books (my university too) and we had the Java books. We did use them but Javadocs on the web started to be faster to use than books. Then every reference on the web has been more up to date than any book. Javascript, Ruby, Python, PHP, Elixir, Erlang all of them online. I'm sure that I'm forgetting a bunch of other languages. Blogs are about as good as books about patterns, ideas, best practices etc. I just didn't see the point of buying paper when I could read the same things on a screen for free.