---
title: "union(_:)"
framework: foundation
role: symbol
role_heading: Instance Method
path: "foundation/nsmutableorderedset/union(_:)"
---

# union(_:)

Adds each object in another given ordered set to the receiving mutable ordered set, if not present.

## Declaration

```swift
func union(_ other: NSOrderedSet)
```

## Parameters

- `other`: The set of objects to add to the receiving mutable ordered set.

## See Also

### Combining and Recombining Entries

- [intersect(_:)](foundation/nsmutableorderedset/intersect(_:).md)
- [intersectSet(_:)](foundation/nsmutableorderedset/intersectset(_:).md)
- [minus(_:)](foundation/nsmutableorderedset/minus(_:).md)
- [minusSet(_:)](foundation/nsmutableorderedset/minusset(_:).md)
- [unionSet(_:)](foundation/nsmutableorderedset/unionset(_:).md)