# PartialRangeUpTo A partial half-open interval up to, but not including, an upper bound. ``` @frozen struct PartialRangeUpTo where Bound : Comparable ``` ## Overview You create `PartialRangeUpTo` instances by using the prefix half-open range operator (prefix `..<`). ``` let upToFive = ..<5.0 ``` You can use a `PartialRangeUpTo` instance to quickly check if a value is contained in a particular range of values. For example: ``` upToFive.contains(3.14) // true upToFive.contains(6.28) // false upToFive.contains(5.0) // false ``` You can use a `PartialRangeUpTo` instance of a collection’s indices to represent the range from the start of the collection up to, but not including, the partial range’s upper bound. ``` let numbers = [10, 20, 30, 40, 50, 60, 70] print(numbers[..<3]) // Prints "[10, 20, 30]" ``` --- 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)