# format(_:) Formats a floating-point value, using this style. ``` func format(_ value: Value) -> String ``` ## Parameters `value` The floating-point value to format. ## Return Value A string representation of `value`, formatted according to the style’s configuration. ## Discussion Use this method when you want to create a single style instance and use it to format multiple floating-point values. The following example creates a style that uses the `en_US` locale, then adds the [`scientific`](/documentation/Foundation/NumberFormatStyleConfiguration/Notation/scientific) modifier. It applies this style to all the floating-point values in an array. ```swift let scientificStyle = FloatingPointFormatStyle( locale: Locale(identifier: "en_US")) .notation(.scientific) let nums = [100.1, 1000.2, 10000.3, 100000.4, 1000000.5] let formattedNums = nums.map { scientificStyle.format($0) } // ["1.001E2", "1.0002E3", "1.00003E4", "1.000004E5", "1E6"] ``` To format a single floating-point value, use the instance method , passing in an instance of [`FloatingPointFormatStyle`](/documentation/Foundation/FloatingPointFormatStyle), or to use a default style. --- 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)