# byteCount(style:allowedUnits:spellsOutZero:includesActualByteCount:) Returns a format style to format a data storage value represented with Foundation’s measurement type. ``` static func byteCount(style: Measurement.FormatStyle.ByteCount.Style, allowedUnits: Measurement.FormatStyle.ByteCount.Units = .all, spellsOutZero: Bool = true, includesActualByteCount: Bool = false) -> Self ``` ## Parameters `style` The style of byte count to express, such as memory or file system storage. `allowedUnits` The units the format style can use to express the byte count. `spellsOutZero` A Boolean value that indicates whether the format style should spell out zero-byte values as text, like `Zero kB`. `includesActualByteCount` A Boolean value that indicates whether the format style should include the exact byte count, in addition to expressing it in terms of units. For example, `1 kB (1,024 bytes)`. ## Return Value A format style for formatting a measurement of data storage, customized with the provided behaviors. ## Discussion Use this type method when the call point allows the use of [`Measurement.FormatStyle.ByteCount`](/documentation/Foundation/Measurement/FormatStyle/ByteCount). You typically do this when calling the [`formatted()`](/documentation/Foundation/Measurement/formatted()) on a [`Measurement`](/documentation/Foundation/Measurement) whose unit type is [`UnitInformationStorage`](/documentation/Foundation/UnitInformationStorage), as seen in the following example. ```swift let count = Measurement(value: 1024, unit: UnitInformationStorage.bytes) let formatted = count.formatted(.byteCount(style: .memory)) // "1 kB" ``` --- 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)