---
title: "init(bitmapRepresentation:)"
framework: foundation
role: symbol
role_heading: Initializer
path: "foundation/nscharacterset/init(bitmaprepresentation:)"
---

# init(bitmapRepresentation:)

Returns a character set containing characters determined by a given bitmap representation.

## Declaration

```swift
init(bitmapRepresentation data: Data)
```

## Parameters

- `data`: A bitmap representation of a character set.

## Return Value

Return Value A character set containing characters determined by data.

## Discussion

Discussion This method is useful for creating a character set object with data from a file or other external data source. A raw bitmap representation of a character set is a byte array with the first 2^16 bits (that is, 8192 bytes) representing the code point range of the the Basic Multilingual Plane (BMP), such that the value of the bit at position n represents the presence in the character set of the character with decimal Unicode value n. A bitmap representation may contain zero to sixteen additional 8192 byte segments to for each additional Unicode plane containing a character in a character set, with each 8192 byte segment prepended with a single plane index byte. To add a character in the Basic Multilingual Plane (BMP) with decimal Unicode value n to a raw bitmap representation, you might do the following: unsigned char bitmapRep[8192]; bitmapRep[n >> 3] |= (((unsigned int)1) << (n & 7)); To remove that character: bitmapRep[n >> 3] &= ~(((unsigned int)1) << (n & 7));

## See Also

### Creating and Managing Character Sets as Bitmap Representations

- [init(contentsOfFile:)](foundation/nscharacterset/init(contentsoffile:).md)
- [bitmapRepresentation](foundation/nscharacterset/bitmaprepresentation.md)