Instance Method

dropLast(_:)

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

Declaration

func dropLast(_ k: Int) -> Substring

Parameters

k

The number of elements to drop off the end of the collection. k must be greater than or equal to zero.

Return Value

A subsequence that leaves off k elements from the end.

Discussion

If the number of elements to drop exceeds the number of elements in the collection, the result is an empty subsequence.

let numbers = [1, 2, 3, 4, 5]
print(numbers.dropLast(2))
// Prints "[1, 2, 3]"
print(numbers.dropLast(10))
// Prints "[]"

Complexity: O(1) if the collection conforms to RandomAccessCollection; otherwise, O(k), where k is the number of elements to drop.

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 removeAll(where: (Character) -> Bool)

Removes all the elements that satisfy the given predicate.

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 popLast() -> Character?

Removes and returns the last element of the collection.