---
title: collectionJoinBehavior
framework: uikit
role: symbol
role_heading: Instance Property
path: uikit/uiscene/activationrequestoptions/collectionjoinbehavior
---

# collectionJoinBehavior

The behavior that specifies how a new scene joins a scene collection.

## Declaration

```swift
var collectionJoinBehavior: UISceneCollectionJoinBehavior { get set }
```

## Discussion

Discussion A scene collection is a group of scenes that display together. In apps built with Mac Catalyst, you use this behavior to add windows to an NSWindowTabGroup.

## See Also

### Specifying collection join behavior

- [UISceneCollectionJoinBehavior](uikit/uiscenecollectionjoinbehavior.md)