Returns a partial range up to, and including, its upper bound.
SDKs
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 11.0+
Framework
- Dispatch
Declaration
prefix static func ... (maximum: DispatchParameters
maximumThe upper bound for the range.
Discussion
Use the prefix closed range operator (prefix ...) to create a partial range of any type that conforms to the Comparable protocol. This example creates a Partial instance that includes any value less than or equal to 5.
let throughFive = ...5.0
throughFive.contains(4.0) // true
throughFive.contains(5.0) // true
throughFive.contains(6.0) // false
You can use this type of partial range of a collection’s indices to represent the range from the start of the collection up to, and including, the partial range’s upper bound.
let numbers = [10, 20, 30, 40, 50, 60, 70]
print(numbers[...3])
// Prints "[10, 20, 30, 40]"