# grouping(_:) Modifies the format style to use the specified grouping. ``` func grouping(_ group: Decimal.FormatStyle.Configuration.Grouping) -> Decimal.FormatStyle ``` ## Parameters `group` The grouping to apply to the format style. ## Return Value A decimal format style modified to use the specified grouping. ## Discussion The following example creates a default [`Decimal.FormatStyle`](/documentation/Foundation/Decimal/FormatStyle) for the `en_US` locale, and a second style that never uses grouping. It then applies each style to an array of decimal values. The formatting that the modified style applies eliminates the three-digit grouping usually performed for the `en_US` locale. ```swift let defaultStyle = FloatingPointFormatStyle(locale: Locale(identifier: "en_US")) let neverStyle = defaultStyle.grouping(.never) let nums = [100.1, 1000.2, 10000.3, 100000.4, 1000000.5] let defaultNums = nums.map { defaultStyle.format($0) } // ["100.1", "1,000.2", "10,000.3", "100,000.4", "1,000,000.5"] let neverNums = nums.map { neverStyle.format($0) } // ["100.1", "1000.2", "10000.3", "100000.4", "1000000.5"] ``` --- 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)