Interesting question! Let's test:

JS Benchmark for several floor function alternatives

Results: Math.floor is about the same speed as other numeric methods for flooring a number, and all are far faster than you'll ever have to worry about.

Conclusion: Use Math.floor for readability, but these kinds of micro-optimisations really do not matter lol.

I think he definitely did it cause it was fancier lol. There's no need to do it

foi isso que pensei tambem

The third generate function member is a lambda function. [] brackets for variables initialized outside lambda. mutable used here in order to be able modify the k variable.

"#{ VALUE } Chinese Yuan" — is effectively equal to VALUE + " Chinese Yuan"
"%0.2f" % VALUE — here % is a method on String instances, it formats given VALUE using this string
(in this case 0.2f formats a number, result of usd * 6.75 expression, with precision of two digits after the dot)

As a guess, I'd say 32 is the smallest power of 2 that is large enough for either of the answers.

Some people like to keep everything in powers of 2 (so your code would have s[128] instead) for "efficiency".

Someone more experimented may correct me or give more precision, but I understood that using bitwise operators was generally way more efficient. Though in a kata like this one it probably makes no significant difference. From now I generally try to use prioritarily them when they are appropriated.

Here rbegin() start from last it also called reverse beginning . Same for rend() also . Generally sort function return ascending order sort then descending is just reverse of it .

Thanks

I think, that in general, .at() is safer than [] in terms of exceptions throwing.