Returns the last element of the sequence that satisfies the given predicate.
SDK
- Xcode 10.0+
Framework
- Swift Standard Library
Declaration
func last(where predicate: (Element) throws -> Bool) rethrows -> Element?
Parameters
predicateA closure that takes an element of the sequence as its argument and returns a Boolean value indicating whether the element is a match.
Return Value
The last element of the sequence that satisfies predicate, or nil if there is no element that satisfies predicate.
Discussion
This example uses the last(where:) method to find the last negative number in an array of integers:
let numbers = [3, 7, 4, -2, 9, -6, 10, 1]
if let lastNegative = numbers.last(where: { $0 < 0 }) {
print("The last negative number is \(lastNegative).")
}
// Prints "The last negative number is -6."
Complexity: O(n), where n is the length of the collection.