# init(locale:) Creates an integer format style that uses the given locale. ``` init(locale: Locale = .autoupdatingCurrent) ``` ## Parameters `locale` The locale to use when formatting or parsing integers. Defaults to [`autoupdatingCurrent`](/documentation/Foundation/Locale/autoupdatingCurrent). ## Discussion Create an [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) when you intend to apply a given style to multiple integers. The following example creates a style that uses the `en_US` locale, which uses three-based grouping and comma separators. It then applies this style to all the integers in an array. ```swift let enUSstyle = IntegerFormatStyle(locale: Locale(identifier: "en_US")) let nums = [100, 1000, 10000, 100000, 1000000] let formattedNums = nums.map { enUSstyle.format($0) } // ["100", "1,000", "10,000", "100,000", "1,000,000"] ``` To format a single integer, you can use the instance method , passing in an instance of [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)