---
title: "ArgumentMatcher.keyOnly(argumentName:)"
framework: evaluations
role: symbol
role_heading: Case
path: "evaluations/argumentmatcher/keyonly(argumentname:)"
---

# ArgumentMatcher.keyOnly(argumentName:)

A value that indicates that the argument must be present with this key and no specific value.

## Declaration

```swift
case keyOnly(argumentName: String)
```

## See Also

### Exact matching

- [ArgumentMatcher.exact(argumentName:value:)](evaluations/argumentmatcher/exact(argumentname:value:).md)