Instance Method

removeAll(where:)

Removes all the elements that satisfy the given predicate.

Declaration

mutating func removeAll(where shouldBeRemoved: (Character) throws -> Bool) rethrows

Parameters

shouldBeRemoved: A closure that takes an element of the sequence as its argument and returns a Boolean value indicating whether the element should be removed from the collection.

Discussion

Use this method to remove every element in a collection that meets particular criteria. The order of the remaining elements is preserved. This example removes all the vowels from a string:

var phrase = "The rain in Spain stays mainly in the plain."

let vowels: Set<Character> = ["a", "e", "i", "o", "u"]
phrase.removeAll(where: { vowels.contains($0) })
// phrase == "Th rn n Spn stys mnly n th pln."

Complexity: O(n), where n is the length of the collection.

See Also

Removing Substrings

func remove(at: String.Index) -> Character

Removes and returns the character at the specified position.

func removeAll(keepingCapacity: Bool)

Replaces this string with the empty string.

func removeFirst() -> Character

Removes and returns the first element of the collection.

func removeFirst(Int)

Removes the specified number of elements from the beginning of the collection.

func removeLast() -> Character

Removes and returns the last element of the collection.

func removeLast(Int)

Removes the specified number of elements from the end of the collection.

func removeSubrange(Range<String.Index>)

Removes the characters in the given range.

func removeSubrange<R>(R)

Removes the elements in the specified subrange from the collection.

func filter((Character) -> Bool) -> String

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

func drop(while: (Character) -> Bool) -> Substring

Returns a subsequence by skipping elements while predicate returns true and returning the remaining elements.

func dropFirst(Int) -> Substring

Returns a subsequence containing all but the given number of initial elements.

func dropLast(Int) -> Substring

Returns a subsequence containing all but the specified number of final elements.

func popLast() -> Character?

Removes and returns the last element of the collection.