# precision(_:) Modifies the format style to use the specified precision. ``` func precision(_ p: IntegerFormatStyle.Configuration.Precision) -> IntegerFormatStyle ``` ## Parameters `p` The precision to apply to the format style. ## Return Value An integer format style modified to use the specified precision. ## Discussion The [`NumberFormatStyleConfiguration.Precision`](/documentation/Foundation/NumberFormatStyleConfiguration/Precision) type lets you specify a fixed number of digits to show for a number’s integer and fractional parts, although [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) only uses the former. You can also set a fixed number of significant digits. The following example creates a default [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) for the `en_US` locale, and a second style that uses a maximum of four significant digits. It then applies each style to an array of integers. The formatting that the modified style applies truncates precision to `0` after the fourth most significant digit. ```swift let defaultStyle = IntegerFormatStyle(locale: Locale(identifier: "en_US")) let precisionStyle = defaultStyle.precision(.significantDigits(1...4)) let nums = [123, 1234, 12345, 123456, 1234567] let defaultNums = nums.map { defaultStyle.format($0) } // ["123", "1,234", "12,345", "123,456", "1,234,567"] let precisionNums = nums.map { precisionStyle.format($0) } // ["123", "1,234", "12,340", "123,500", "1,235,000"] ``` --- 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)