Create a new array and modify elements on an offset index

Can you tell me a little more about what index vs charAt serves as? I cannot find the method called index, only indexOf. Is that the method you are referring to?

Never mind, you are talking about using index in the function. Sorry.

I made all of those variable changes you suggested, thanks. Here is what I got when using the index and not charAt() method:

const firstLetter = word[index=0].toUpperCase();