# isLessThanOrEqualTo(_:) Returns a Boolean value indicating whether this instance is less than or equal to the given value. ``` func isLessThanOrEqualTo(_ other: Self) -> Bool ``` ## Parameters `other` The value to compare with this value. ## Return Value `true` if `other` is greater than this value; 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 less-than-or-equal-to operator (`<=`) for floating-point values. Some special cases apply: - Because NaN is incomparable with any value, this method returns `false` when called on NaN or when NaN is passed as `other`. - `-infinity` compares less than or equal to all values except NaN. - Every value except NaN compares less than or equal to `+infinity`. The following example shows the behavior of the `isLessThanOrEqualTo(_:)` method with different kinds of values: ``` let x = 15.0 x.isLessThanOrEqualTo(20.0) // true x.isLessThanOrEqualTo(.nan) // false Double.nan.isLessThanOrEqualTo(x) // false ``` The `isLessThanOrEqualTo(_:)` method implements the less-than-or-equal 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)