# IntegerFormatStyle A structure that converts between integer values and their textual representations. ``` struct IntegerFormatStyle where Value : BinaryInteger ``` ## Overview Instances of [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) create localized, human-readable text from numbers and parse string representations of numbers into instances of types. All of the Swift standard library’s integer types, such as and , conform to , and therefore work with this format style. [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) includes two nested types, [`IntegerFormatStyle.Percent`](/documentation/Foundation/IntegerFormatStyle/Percent) and [`IntegerFormatStyle.Currency`](/documentation/Foundation/IntegerFormatStyle/Currency), for working with percentages and currencies. Each format style includes a configuration that determines how it represents numeric values, for things like grouping, displaying signs, and variant presentations like scientific notation. [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) and [`IntegerFormatStyle.Percent`](/documentation/Foundation/IntegerFormatStyle/Percent) include a [`NumberFormatStyleConfiguration`](/documentation/Foundation/NumberFormatStyleConfiguration), and [`IntegerFormatStyle.Currency`](/documentation/Foundation/IntegerFormatStyle/Currency) includes a [`CurrencyFormatStyleConfiguration`](/documentation/Foundation/CurrencyFormatStyleConfiguration). You can customize numeric formatting for a style by adjusting its backing configuration. The system automatically caches unique configurations of a format style to enhance performance. > Note: > Foundation provides another format style type, ``doc://com.apple.foundation/documentation/Foundation/FloatingPointFormatStyle``, for working with numbers that conform to . For Foundation’s ``doc://com.apple.foundation/documentation/Foundation/Decimal`` type, use ``doc://com.apple.foundation/documentation/Foundation/Decimal/FormatStyle``. ### Formatting integers Use the method to create a string representation of an integer using the default [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) configuration. ```swift let formattedDefault = 123456.formatted() // formattedDefault is "123,456" in en_US locale. // Other locales may use different separator and grouping behavior. ``` You can specify a format style by providing an argument to the method. The following example shows the number `12345` represented in each of the available styles, in the `en_US` locale: ```swift let number = 123456 let formattedNumber = number.formatted(.number) // formattedNumber is "123,456". let formattedPercent = number.formatted(.percent) // formattedPercent is "123,456%". let formattedCurrency = number.formatted(.currency(code: "USD")) // formattedCurrency is "$123,456.00". ``` Each style provides methods for updating its numeric configuration, including the number of significant digits, grouping length, and more. You can specify a numeric configuration by calling as many of these methods as you need in any order you choose. The following example shows the same number with default and custom configurations: ```swift let exampleNumber = 123456 let defaultFormatting = exampleNumber.formatted(.number) // defaultFormatting is "125 000" for the "fr_FR" locale // defaultFormatting is "125000" for the "jp_JP" locale // defaultFormatting is "125,000" for the "en_US" locale let customFormatting = exampleNumber.formatted( .number .grouping(.never) .sign(strategy: .always())) // customFormatting is "+123456" ``` ### Creating an integer format style instance The previous examples use static factory methods like [`number`](/documentation/Foundation/FormatStyle/number-7fxvo) to create format styles within the call to the method. You can also create an [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) instance and use it to repeatedly format different values with the [`format(_:)`](/documentation/Foundation/IntegerFormatStyle/format(_:)) method: ```swift let percentFormatStyle = IntegerFormatStyle.Percent() percentFormatStyle.format(50) // "50%" percentFormatStyle.format(85) // "85%" percentFormatStyle.format(100) // "100%" ``` ### Parsing integers You can use [`IntegerFormatStyle`](/documentation/Foundation/IntegerFormatStyle) to parse strings into integer values. You can define the format style within the type’s initializer or pass in a format style you create prior to calling the method, as shown here: ```swift let price = try? Int("$123,456", format: .currency(code: "USD")) // 123456 let priceFormatStyle = IntegerFormatStyle.Currency(code: "USD") let salePrice = try? Int("$120,000", format: priceFormatStyle) // 120000 ``` ### Matching regular expressions Along with parsing numeric values in strings, you can use the Swift regular expression domain-specific language to match and capture numeric substrings. The following example defines a currency format style to match and capture a currency value using US dollars and `en_US` numeric conventions. The rest of the regular expression ignores any characters prior to a `": "` sequence that precedes the currency substring. ```swift import RegexBuilder let source = "Payment due: $123,456" let matcher = Regex { OneOrMore(.any) ": " Capture { One(.localizedIntegerCurrency(code: Locale.Currency("USD"), locale: Locale(identifier: "en_US"))) } } let match = source.firstMatch(of: matcher) let localizedInteger = match?.1 // 123456 ``` ## Topics ### Creating an integer format style [`init(locale:)`](/documentation/Foundation/IntegerFormatStyle/init(locale:)) Creates an integer format style that uses the given locale. ### Formatting integer values [`format(_:)`](/documentation/Foundation/IntegerFormatStyle/format(_:)) Formats an integer, using this style. ### Customizing style behavior [`decimalSeparator(strategy:)`](/documentation/Foundation/IntegerFormatStyle/decimalSeparator(strategy:)) Modifies the format style to use the specified decimal separator display strategy. [`grouping(_:)`](/documentation/Foundation/IntegerFormatStyle/grouping(_:)) Modifies the format style to use the specified grouping. [`notation(_:)`](/documentation/Foundation/IntegerFormatStyle/notation(_:)) Modifies the format style to use the specified notation. [`precision(_:)`](/documentation/Foundation/IntegerFormatStyle/precision(_:)) Modifies the format style to use the specified precision. [`rounded(rule:increment:)`](/documentation/Foundation/IntegerFormatStyle/rounded(rule:increment:)) Modifies the format style to use the specified rounding rule and increment. [`scale(_:)`](/documentation/Foundation/IntegerFormatStyle/scale(_:)) Modifies the format style to use the specified scale. [`sign(strategy:)`](/documentation/Foundation/IntegerFormatStyle/sign(strategy:)) Modifies the format style to use the specified sign display strategy for displaying or omitting sign symbols. [`IntegerFormatStyle.Configuration`](/documentation/Foundation/IntegerFormatStyle/Configuration) The type the format style uses for configuration settings. [`NumberFormatStyleConfiguration`](/documentation/Foundation/NumberFormatStyleConfiguration) Configuration settings for formatting numbers of different types. ### Acessing style locale [`locale`](/documentation/Foundation/IntegerFormatStyle/locale) The locale of the format style. ### Applying currency styles [`IntegerFormatStyle.Currency`](/documentation/Foundation/IntegerFormatStyle/Currency) A format style that converts between integer currency values and their textual representations. ### Applying measurement styles [`Measurement.FormatStyle`](/documentation/Foundation/Measurement/FormatStyle) A type that provides localized representations of measurements. ### Applying list styles [`ListFormatStyle`](/documentation/Foundation/ListFormatStyle) A type that formats lists of items with a separator and conjunction appropriate for a given locale. ### Creating attributed strings [`attributed`](/documentation/Foundation/IntegerFormatStyle/attributed-swift.property) An attributed format style based on the integer format style. [`IntegerFormatStyle.Attributed`](/documentation/Foundation/IntegerFormatStyle/Attributed-swift.struct) A format style that converts integers into attributed strings. ### Parsing integers [`IntegerParseStrategy`](/documentation/Foundation/IntegerParseStrategy) A parse strategy for creating integer values from formatted strings. ### Supporting types [`IntegerFormatStyle.Currency`](/documentation/Foundation/IntegerFormatStyle/Currency) A format style that converts between integer currency values and their textual representations. [`IntegerFormatStyle.Percent`](/documentation/Foundation/IntegerFormatStyle/Percent) A format style that converts between integer percentage values and their textual representations. --- 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)