---
title: "CFCharacterSetUnion(_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfcharactersetunion(_:_:)"
---

# CFCharacterSetUnion(_:_:)

Forms the union of two character sets.

## Declaration

```swift
func CFCharacterSetUnion(_ theSet: CFMutableCharacterSet!, _ theOtherSet: CFCharacterSet!)
```

## Parameters

- `theSet`: The source character set, modified by union with theOtherSet.
- `theOtherSet`: The character set with which the union is formed.

## See Also

### Logical Operations

- [CFCharacterSetIntersect(_:_:)](corefoundation/cfcharactersetintersect(_:_:).md)
- [CFCharacterSetInvert(_:)](corefoundation/cfcharactersetinvert(_:).md)