---
title: parameterString
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/nsurl/parameterstring
---

# parameterString

The parameter string conforming to RFC 1808. (read-only)

## Declaration

```swift
var parameterString: String? { get }
```

## Discussion

Discussion This property contains the parameter string. Any percent-encoded characters are not unescaped. If the receiver does not conform to RFC 1808, this property contains nil.  For example, in the URL file:///path/to/file;foo, the parameter string is foo. This property should not be confused with the query property, which also often contains a string of parameters.

## See Also

### Accessing the Parts of the URL

- [absoluteString](foundation/nsurl/absolutestring.md)
- [absoluteURL](foundation/nsurl/absoluteurl.md)
- [baseURL](foundation/nsurl/baseurl.md)
- [fileSystemRepresentation](foundation/nsurl/filesystemrepresentation.md)
- [fragment](foundation/nsurl/fragment.md)
- [host](foundation/nsurl/host.md)
- [lastPathComponent](foundation/nsurl/lastpathcomponent.md)
- [password](foundation/nsurl/password.md)
- [path](foundation/nsurl/path.md)
- [pathComponents](foundation/nsurl/pathcomponents.md)
- [pathExtension](foundation/nsurl/pathextension.md)
- [port](foundation/nsurl/port.md)
- [query](foundation/nsurl/query.md)
- [relativePath](foundation/nsurl/relativepath.md)
- [relativeString](foundation/nsurl/relativestring.md)