Instance Method

filter(_:)

Returns an array containing, in order, the elements of the sequence that satisfy the given predicate.

Declaration

func filter(_ isIncluded: (UInt8) throws -> Bool) rethrows -> [UInt8]

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 array.

Return Value

An array 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 sequence.

See Also

Selecting Bytes

func prefix(Int) -> PrefixSequence<SHA256Digest>

Returns a sequence, up to the specified maximum length, containing the initial elements of the sequence.

func prefix(while: (UInt8) -> Bool) -> [UInt8]

Returns a sequence containing the initial, consecutive elements that satisfy the given predicate.

func suffix(Int) -> [UInt8]

Returns a subsequence, up to the given maximum length, containing the final elements of the sequence.