---
title: "boundary(withIdentifier:)"
framework: uikit
role: symbol
role_heading: Instance Method
path: "uikit/uicollisionbehavior/boundary(withidentifier:)"
---

# boundary(withIdentifier:)

Returns a specified Bezier-path boundary.

## Declaration

```swift
func boundary(withIdentifier identifier: any NSCopying) -> UIBezierPath?
```

## Parameters

- `identifier`: A boundary identifier that you’ve previously added to the collision behavior.

## Return Value

Return Value A Bezier-path boundary.

## See Also

### Configuring a collision behavior

- [addBoundary(withIdentifier:for:)](uikit/uicollisionbehavior/addboundary(withidentifier:for:).md)
- [addBoundary(withIdentifier:from:to:)](uikit/uicollisionbehavior/addboundary(withidentifier:from:to:).md)
- [boundaryIdentifiers](uikit/uicollisionbehavior/boundaryidentifiers.md)
- [collisionMode](uikit/uicollisionbehavior/collisionmode.md)
- [removeAllBoundaries()](uikit/uicollisionbehavior/removeallboundaries().md)
- [removeBoundary(withIdentifier:)](uikit/uicollisionbehavior/removeboundary(withidentifier:).md)
- [setTranslatesReferenceBoundsIntoBoundary(with:)](uikit/uicollisionbehavior/settranslatesreferenceboundsintoboundary(with:).md)
- [translatesReferenceBoundsIntoBoundary](uikit/uicollisionbehavior/translatesreferenceboundsintoboundary.md)