---
title: "append(_:)"
framework: foundation
role: symbol
role_heading: Instance Method
path: "foundation/data/append(_:)-xtlw"
---

# append(_:)

Append a buffer of bytes to the data.

## Declaration

```swift
mutating func append<SourceType>(_ buffer: UnsafeBufferPointer<SourceType>)
```

## Parameters

- `buffer`: The buffer of bytes to append. The size is calculated from SourceType and buffer.count.

## See Also

### Adding Bytes

- [append(_:)](foundation/data/append(_:)-vjwy.md)
- [append(_:count:)](foundation/data/append(_:count:).md)
- [reserveCapacity(_:)](foundation/data/reservecapacity(_:).md)