---
title: "CFURLCreateStringByReplacingPercentEscapes(_:_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfurlcreatestringbyreplacingpercentescapes(_:_:_:)"
---

# CFURLCreateStringByReplacingPercentEscapes(_:_:_:)

Creates a new string by replacing any percent escape sequences with their character equivalent.

## Declaration

```swift
func CFURLCreateStringByReplacingPercentEscapes(_ allocator: CFAllocator!, _ originalString: CFString!, _ charactersToLeaveEscaped: CFString!) -> CFString!
```

## Parameters

- `allocator`: The allocator to use to allocate memory for the new CFString object. Pass NULL or doc://com.apple.corefoundation/documentation/CoreFoundation/kCFAllocatorDefault to use the current default allocator.
- `originalString`: The CFString object to be copied and modified.
- `charactersToLeaveEscaped`: Characters whose percent escape sequences, such as %20 for a space character, you want to leave intact. Pass NULL to specify that no percent escapes be replaced, or the empty string (CFSTR("")) to specify that all be replaced.

## Return Value

Return Value A new CFString object, or NULL if the percent escapes cannot be converted to characters, assuming UTF-8 encoding. If no characters need to be replaced, this function returns the original string with its reference count incremented. Ownership follows the create rule. See The Create Rule.

## See Also

### Converting URLs to Other Representations

- [CFURLCreateData(_:_:_:_:)](corefoundation/cfurlcreatedata(_:_:_:_:).md)
- [CFURLCreateStringByAddingPercentEscapes(_:_:_:_:_:)](corefoundation/cfurlcreatestringbyaddingpercentescapes(_:_:_:_:_:).md)
- [CFURLCreateStringByReplacingPercentEscapesUsingEncoding(_:_:_:_:)](corefoundation/cfurlcreatestringbyreplacingpercentescapesusingencoding(_:_:_:_:).md)
- [CFURLGetFileSystemRepresentation(_:_:_:_:)](corefoundation/cfurlgetfilesystemrepresentation(_:_:_:_:).md)
- [CFURLGetFSRef(_:_:)](corefoundation/cfurlgetfsref(_:_:).md)
- [CFURLGetString(_:)](corefoundation/cfurlgetstring(_:).md)