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Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
Hahaha
Could be more clear stating that natural numbers here are including 0, not all definitions of natural numbers agree on that. https://math.stackexchange.com/questions/283/is-0-a-natural-number
This class terminology is not so clear in the js land, yet. I've got a little frustrated figuring out that I should just put the function inside the other function.
What would this return?
"Hello.#world"
You can find more info here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace#Specifying_a_function_as_a_parameter
I think that maybe it should be warned that you can't change the original list. Or it doesn't make sense to warn that?