Instance Method

filter(_:)

Returns a new collection of the same type containing, in order, the elements of the original collection that satisfy the given predicate.

Declaration

func filter(_ isIncluded: (Self.Element) throws -> Bool) rethrows -> Self

Parameters

isIncluded

A 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 collection.

Return Value

A collection of the elements that isIncluded 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 collection.