---
title: FloatingPointClassification.signalingNaN
framework: swift
role: symbol
role_heading: Case
path: swift/floatingpointclassification/signalingnan
---

# FloatingPointClassification.signalingNaN

A signaling NaN (“not a number”).

## Declaration

```swift
case signalingNaN
```

## Discussion

Discussion A signaling NaN sets the floating-point exception status when used in many floating-point operations.