NullHypothesis NullHypothesis - 1 month ago 6
iOS Question

Decimals in Swift

I am writing a Swift app and am dealing with decimals in a database (stored in mysql as decimals, with 2 digits. Basically it's sales someone made each day, so generally anything from $0 to $1000, but not millions, and nothing insane in terms of trailing decimals, just always rounded to 2 decimal places).

Referencing this helped me out:
How to properly format currency on ios

..But I wanted to just do a quick sanity check here and make sure this strategy is ok.
i.e I would use NSDecimal or NSDecimalNumber (is there a preferred swift equivalent??)

What would you all recommend I do when dealing with currency in Swift? I'd like to use the locale-based currency symbol as well. I have a class called Sales that contains the amount in question. What do you recommend the datatype to be?

Apologies if I am coming off lazy, I actually have some ideas on what to do but feel a little overwhelmed at the "right" approach, especially in a locale-sensitive way, and wanted to check in here with you all.

Thanks so much!

Answer

NSDecimal is not really supported in Swift (it's a weird opaque pointer type), but NSDecimalNumber is — and as in Obj-C, it's the best thing to use for base-ten arithmetic (because it actually does its operations in base ten). NSLocale, NSNumberFormatter and friends all work too and should satisfy your localization needs.