---
title: FSExtentType.data
framework: fskit
role: symbol
role_heading: Case
path: fskit/fsextenttype/data
---

# FSExtentType.data

An extent type to indicate valid data.

## Declaration

```swift
case data
```

## Discussion

Discussion Use this type for all extents on a file system that doesn’t support sparse files. tip: The kernel keeps track of the end of file, so it knows a range of [EOF, allocated space] is uninitialized. Because of this behavior, it’s valid to pass the data extent type for such a range.

## See Also

### Working with extent types

- [FSExtentType.zeroFill](fskit/fsextenttype/zerofill.md)
- [FSExtentType.readOnly](fskit/fsextenttype/readonly.md)