---
title: isCanonical
framework: swift
role: symbol
role_heading: Instance Property
path: swift/float/iscanonical
---

# isCanonical

A Boolean value indicating whether the instance’s representation is in its canonical form.

## Declaration

```swift
var isCanonical: Bool { get }
```

## Discussion

Discussion The IEEE 754 specification defines a canonical, or preferred, encoding of a floating-point value. On platforms that fully support IEEE 754, every Float or Double value is canonical, but non-canonical values can exist on other platforms or for other types. Some examples: On platforms that flush subnormal numbers to zero (such as armv7 with the default floating-point environment), Swift interprets subnormal Float and Double values as non-canonical zeros. (In Swift 5.1 and earlier, isCanonical is true for these values, which is the incorrect value.) On i386 and x86_64, Float80 has a number of non-canonical encodings. “Pseudo-NaNs”, “pseudo-infinities”, and “unnormals” are interpreted as non-canonical NaN encodings. “Pseudo-denormals” are interpreted as non-canonical encodings of subnormal values. Decimal floating-point types admit a large number of non-canonical encodings. Consult the IEEE 754 standard for additional details.

## See Also

### Querying a Float’s State

- [isZero](swift/float/iszero.md)
- [isFinite](swift/float/isfinite.md)
- [isInfinite](swift/float/isinfinite.md)
- [isNaN](swift/float/isnan.md)
- [isSignalingNaN](swift/float/issignalingnan.md)
- [isNormal](swift/float/isnormal.md)
- [isSubnormal](swift/float/issubnormal.md)
- [floatingPointClass](swift/float/floatingpointclass.md)