---
title: negate()
framework: swift
role: symbol
role_heading: Instance Method
path: swift/float80/negate()
---

# negate()

Replaces this value with its additive inverse.

## Declaration

```swift
mutating func negate()
```

## Discussion

Discussion The result is always exact. This example uses the negate() method to negate the value of the variable x: var x = 21.5 x.negate() // x == -21.5