Definitely looks more "code-y" but uses extra memory for variables and unnecessary loops.

while numbers.reduce would allow for scores of any length, that is not necessary for the prompt requirements and is actually overengineered for this task.

Nice. I try to make something similar with Object's iterations and avoid using a 'typical' if-else construction.
Thanks for showing .hasOwnProperty property for 'for-in' implementation

but
why

Good solution, this one would be O(n) compared to the O(n^2) that are more popular right?

ty

memo[char]?memo[char]+1:1 is not actuallying assigning anything to the memo object (which is used as a table for holding character counts)

No?

It's interesting. The solution is based on NaN != NaN, isn't it?

I imagine getting a new job and my first task is tweak this code. I think I would resign right there. Nicely done though 👀

Excellent!