Returns an array containing, in order, the elements of the sequence that satisfy the given predicate.
SDK
- Xcode 9.0+
Framework
- Swift Standard Library
Declaration
func filter(_ isIncluded: (Key) throws -> Bool) rethrows -> [Key]
Parameters
isIncludedA closure that takes an element of the sequence as its argument and returns a Boolean value indicating whether the element should be included in the returned array.
Return Value
An array of the elements that is allowed.
Discussion
In this example, filter(_:) is used to include only names shorter than five characters.
let cast = ["Vivien", "Marlon", "Kim", "Karl"]
let shortNames = cast.filter { $0.count < 5 }
print(shortNames)
// Prints "["Kim", "Karl"]"
Complexity: O(n), where n is the length of the sequence.