---
title: nextDown
framework: swift
role: symbol
role_heading: Instance Property
path: swift/float/nextdown
---

# nextDown

The greatest representable value that compares less than this value.

## Declaration

```swift
var nextDown: Self { get }
```

## Discussion

Discussion For any finite value x, x.nextDown is less than x. For nan or -infinity, x.nextDown is x itself. The following special cases also apply: If x is infinity, then x.nextDown is greatestFiniteMagnitude. If x is leastNonzeroMagnitude, then x.nextDown is 0.0. If x is zero, then x.nextDown is -leastNonzeroMagnitude. If x is -greatestFiniteMagnitude, then x.nextDown is -infinity.

## See Also

### Querying a Float

- [ulp](swift/float/ulp.md)
- [significand](swift/float/significand.md)
- [exponent](swift/float/exponent-swift.property.md)
- [nextUp](swift/float/nextup.md)
- [binade](swift/float/binade.md)