Different format mask in objective-c and swift

Question

I have a program that have two libraries. One is in Objective-C and one is in Swift.

From my webserver I get format mask and set the format mask in first and second library.

I first library NSNumberFormatter is used so expected format mask is :

 #.#0 mm

But in second, that was updated to swift, they use now String.init(format:), so expected format is:

%1.2f mm

Why swift use different format mask and how to convert one to another?

Answer 1

You cannot convert one to the other. You should probably raise an issue with the authors of the library because it's a breaking change.

NSNumberFormatter uses a completely different set of rules than String(format:) . Also, NumberFormatter is localized. The decimal point . is a pattern to choose either . or , depending on user locale. The . in String(format:) is a literal . .

Nothing to do with Swift or Obj-C. Both APIs are available in both languages.