---
title: NSAttributeDescription.AttributeType
framework: coredata
role: symbol
role_heading: Structure
path: coredata/nsattributedescription/attributetype-swift.struct
---

# NSAttributeDescription.AttributeType

The types of attributes that Core Data supports.

## Declaration

```swift
struct AttributeType
```

## Overview

Overview Core Data attribute types explicitly distinguish between bit size. This allows their values to exist independent of the persistent store that contains them. A scalar option is available for a number of attribute types, in some cases by default.  |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |  note: If your application uses BLOBs (binary large objects), such as image and sound files, you can choose to store their data in a location that’s external to the persistent store.

## Topics

### Attribute Types

- [binaryData](coredata/nsattributedescription/attributetype-swift.struct/binarydata.md)
- [boolean](coredata/nsattributedescription/attributetype-swift.struct/boolean.md)
- [composite](coredata/nsattributedescription/attributetype-swift.struct/composite.md)
- [date](coredata/nsattributedescription/attributetype-swift.struct/date.md)
- [decimal](coredata/nsattributedescription/attributetype-swift.struct/decimal.md)
- [double](coredata/nsattributedescription/attributetype-swift.struct/double.md)
- [float](coredata/nsattributedescription/attributetype-swift.struct/float.md)
- [integer16](coredata/nsattributedescription/attributetype-swift.struct/integer16.md)
- [integer32](coredata/nsattributedescription/attributetype-swift.struct/integer32.md)
- [integer64](coredata/nsattributedescription/attributetype-swift.struct/integer64.md)
- [objectID](coredata/nsattributedescription/attributetype-swift.struct/objectid.md)
- [string](coredata/nsattributedescription/attributetype-swift.struct/string.md)
- [transformable](coredata/nsattributedescription/attributetype-swift.struct/transformable.md)
- [undefined](coredata/nsattributedescription/attributetype-swift.struct/undefined.md)
- [uri](coredata/nsattributedescription/attributetype-swift.struct/uri.md)
- [uuid](coredata/nsattributedescription/attributetype-swift.struct/uuid.md)

## Relationships

### Conforms To

- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [RawRepresentable](swift/rawrepresentable.md)

## See Also

### Managing the type

- [attributeValueClassName](coredata/nsattributedescription/attributevalueclassname.md)
- [type](coredata/nsattributedescription/type.md)
- [attributeType](coredata/nsattributedescription/attributetype-swift.property.md)
- [NSAttributeType](coredata/nsattributetype.md)