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# ByteCountFormatStyle

A format style that provides string representations of byte counts.

```
struct ByteCountFormatStyle
```

## Overview

The following example creates an `Int` representing 1,024 bytes, and then formats it as an expression of memory storage, with the default byte count format style.

```swift
let count: Int64 = 1024
let formatted = count.formatted(.byteCount(style: .memory)) // "1 kB"
```

You can also customize a byte count format style, and use this to format one or more <doc://com.apple.documentation/documentation/Swift/Int64> instances. The following example creates a format style to only use kilobyte units, and to spell out the exact byte count of the measurement.

```swift
let style = ByteCountFormatStyle(style: .memory,                                 
                                 allowedUnits: [.kb],
                                 spellsOutZero: true,
                                 includesActualByteCount: false,
                                 locale: Locale(identifier: "en_US"))
let counts: [Int64] = [0, 1024, 2048, 4096, 8192, 16384, 32768, 65536]
let formatted = counts.map ( {style.format($0) } ) // ["Zero kB", "1 kB", "2 kB", "4 kB", "8 kB", "16 kB", "32 kB", "64 kB"]
```

## Topics

### Creating a byte count style

[`init(style:allowedUnits:spellsOutZero:includesActualByteCount:locale:)`](/documentation/Foundation/ByteCountFormatStyle/init(style:allowedUnits:spellsOutZero:includesActualByteCount:locale:))

Initializes a byte count format style.

[`ByteCountFormatStyle.Units`](/documentation/Foundation/ByteCountFormatStyle/Units)

The units to use when formatting a byte count, such as kilobytes or gigabytes.

### Formatting byte count values

[`format(_:)`](/documentation/Foundation/ByteCountFormatStyle/format(_:))

Formats a numeric byte count, using this style.

### Customizing style behavior

[`style`](/documentation/Foundation/ByteCountFormatStyle/style-swift.property)

The semantic style the format style uses to represent a byte count value.

[`ByteCountFormatStyle.Style`](/documentation/Foundation/ByteCountFormatStyle/Style-swift.enum)

The semantic style to use when formatting a byte count value.

### Accessing style properties

[`allowedUnits`](/documentation/Foundation/ByteCountFormatStyle/allowedUnits)

The units the format style can use to express the byte count.

[`ByteCountFormatStyle.Units`](/documentation/Foundation/ByteCountFormatStyle/Units)

The units to use when formatting a byte count, such as kilobytes or gigabytes.

[`spellsOutZero`](/documentation/Foundation/ByteCountFormatStyle/spellsOutZero)

A Boolean value that indicates whether the format style should spell out zero-byte values as text.

[`includesActualByteCount`](/documentation/Foundation/ByteCountFormatStyle/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.

[`locale`](/documentation/Foundation/ByteCountFormatStyle/locale)

The locale to use to format the numeric part of the byte count.

### Modifying style locale

[`locale(_:)`](/documentation/Foundation/ByteCountFormatStyle/locale(_:))

Modifies the format style to use the specified locale.

### Applying currency styles

### Applying measurement styles

### Applying list styles

### Creating attributed strings

[`attributed`](/documentation/Foundation/ByteCountFormatStyle/attributed-swift.property)

An attributed format style based on the byte count format style.

[`ByteCountFormatStyle.Attributed`](/documentation/Foundation/ByteCountFormatStyle/Attributed-swift.struct)

A format style that converts byte counts into attributed strings.

### Supporting types


---

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