Haven't met them before, thank you!

Hello, what does the => mean? Is it kind of an alternative function notation?

Thank you, should have looked closer.

Nice solution!
I was also contemplating a switch statement, but the computational overhead is allegedly very severe and simple if statements are preferable. Details: http://stackoverflow.com/a/12259830

Very elegant!

I'd like to keep all excellent answers to my coding questions for future reference.
So far I've been bookmarking the katas themselves. Is there a specific subpage listing all my comments/discussions that I'm not seeing?

So because strings are instances of the String object, object methods can also be iterated using brackets. (I don't suppose such dynamic iteration would work with the dot notation.)

This is a very smart solution, thank you!

Wow, I learned so much from reading just one line of code! :)

Hello,

Earlier I struggled with calling functions dynamically, e.g. getting the function name from a variable. I really like your solution of calling either toUpperCase() or toLowerCase().
What is the significance of the brackets? Are they necessary for calling the String functions, or for returning the letter value somehow?

This use of apply() sounds very handy, thank you!

Hey there,

What is the significance of apply() in your code? As far as I know it is used to manually provide meaning for this in the given scope. Is this how you create an array with 0 as default value?

Thanks