Swift Formatstyle

FormatStyle is Swift's modern, type-safe replacement for the old Formatter classes, and this skill covers the full range: numbers, currency, percentages, dates, durations, measurements, person names, lists, byte counts, and URLs. The quick reference table alone will save you digging through documentation every time you need to format a currency or a relative date. What stands out is the focus on locale awareness as an i18n concern even in single-language apps, with a clear boundary drawn between FormatStyle mechanics and broader localization work. The custom FormatStyle section shows you how to build your own conformances when the built-in types don't fit. Duration formatting requires iOS 16+, but everything else works from iOS 15 onward.