---
title: "CFStringTrim(_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfstringtrim(_:_:)"
---

# CFStringTrim(_:_:)

Trims a specified substring from the beginning and end of a CFMutableString object.

## Declaration

```swift
func CFStringTrim(_ theString: CFMutableString!, _ trimString: CFString!)
```

## Parameters

- `theString`: The string to trim. If this value is not a CFMutableString object, an assertion is raised.
- `trimString`: The string to trim from theString. The characters of the trim string are treated as a substring and not individually; for example, if the mutable characters are “abc X” and the trim string is “XY”, the mutable characters are not affected.

## See Also

### CFMutableString Miscellaneous Functions

- [CFStringAppend(_:_:)](corefoundation/cfstringappend(_:_:).md)
- [CFStringAppendCharacters(_:_:_:)](corefoundation/cfstringappendcharacters(_:_:_:).md)
- [CFStringAppendCString(_:_:_:)](corefoundation/cfstringappendcstring(_:_:_:).md)
- [CFStringAppendFormatAndArguments(_:_:_:_:)](corefoundation/cfstringappendformatandarguments(_:_:_:_:).md)
- [CFStringAppendPascalString(_:_:_:)](corefoundation/cfstringappendpascalstring(_:_:_:).md)
- [CFStringCapitalize(_:_:)](corefoundation/cfstringcapitalize(_:_:).md)
- [CFStringCreateMutable(_:_:)](corefoundation/cfstringcreatemutable(_:_:).md)
- [CFStringCreateMutableCopy(_:_:_:)](corefoundation/cfstringcreatemutablecopy(_:_:_:).md)
- [CFStringCreateMutableWithExternalCharactersNoCopy(_:_:_:_:_:)](corefoundation/cfstringcreatemutablewithexternalcharactersnocopy(_:_:_:_:_:).md)
- [CFStringDelete(_:_:)](corefoundation/cfstringdelete(_:_:).md)
- [CFStringFindAndReplace(_:_:_:_:_:)](corefoundation/cfstringfindandreplace(_:_:_:_:_:).md)
- [CFStringFold(_:_:_:)](corefoundation/cfstringfold(_:_:_:).md)
- [CFStringInsert(_:_:_:)](corefoundation/cfstringinsert(_:_:_:).md)
- [CFStringLowercase(_:_:)](corefoundation/cfstringlowercase(_:_:).md)
- [CFStringNormalize(_:_:)](corefoundation/cfstringnormalize(_:_:).md)