---
title: open()
framework: foundation
role: symbol
role_heading: Instance Method
path: foundation/stream/open()
---

# open()

Opens the receiving stream.

## Declaration

```swift
func open()
```

## Discussion

Discussion A stream must be created before it can be opened. Once opened, a stream cannot be closed and reopened.

## See Also

### Using Streams

- [close()](foundation/stream/close().md)