# isEqual(to:) Returns a Boolean value indicating whether this instance is equal to the given value. ``` func isEqual(to other: Float) -> Bool ``` ## Parameters `other` The value to compare with this value. ## Return Value `true` if `other` has the same value as this instance; otherwise, `false`. If either this value or `other` is NaN, the result of this method is `false`. ## Discussion This method serves as the basis for the equal-to operator (`==`) for floating-point values. When comparing two values with this method, `-0` is equal to `+0`. NaN is not equal to any value, including itself. For example: ``` let x = 15.0 x.isEqual(to: 15.0) // true x.isEqual(to: .nan) // false Double.nan.isEqual(to: .nan) // false ``` The `isEqual(to:)` method implements the equality predicate defined by the [IEEE 754 specification](http://ieeexplore.ieee.org/servlet/opac?punumber=4610933). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)