> Now, being as outdated as it is, it can no more be treated as one. Relatively "small" changes were made to Ruby since 2.0, but those changes are everywhere, and they seriously reshaped the language, preferred style, common patterns, and solution. So, one being introduced to language through Pickaxe will immediately be in possession of outdated knowledge.

source: https://www.reddit.com/r/ruby/comments/82ubtj/is_it_still_wo...

I see Picaxe outdated? do you have another resource just to not learn the outdated stuff?