---
title: NSLocalizedFailureReasonErrorKey
framework: foundation
role: symbol
role_heading: Global Variable
path: foundation/nslocalizedfailurereasonerrorkey
---

# NSLocalizedFailureReasonErrorKey

The corresponding value is a localized string representation containing the reason for the failure that, if present, will be returned by localizedFailureReason.

## Declaration

```swift
let NSLocalizedFailureReasonErrorKey: String
```

## See Also

### Constants

- [NSURLErrorKey](foundation/nsurlerrorkey.md)
- [NSFilePathErrorKey](foundation/nsfilepatherrorkey.md)
- [NSHelpAnchorErrorKey](foundation/nshelpanchorerrorkey.md)
- [NSLocalizedDescriptionKey](foundation/nslocalizeddescriptionkey.md)
- [NSLocalizedFailureErrorKey](foundation/nslocalizedfailureerrorkey.md)
- [NSLocalizedRecoveryOptionsErrorKey](foundation/nslocalizedrecoveryoptionserrorkey.md)
- [NSLocalizedRecoverySuggestionErrorKey](foundation/nslocalizedrecoverysuggestionerrorkey.md)
- [NSRecoveryAttempterErrorKey](foundation/nsrecoveryattemptererrorkey.md)
- [NSStringEncodingErrorKey](foundation/nsstringencodingerrorkey.md)
- [NSUnderlyingErrorKey](foundation/nsunderlyingerrorkey.md)
- [NSDebugDescriptionErrorKey](foundation/nsdebugdescriptionerrorkey.md)
- [NSMultipleUnderlyingErrorsKey](foundation/nsmultipleunderlyingerrorskey.md)