Instance Method

split(separator:maxSplits:omittingEmptySubsequences:)

Returns the longest possible subsequences of the sequence, in order, around elements equal to the given element.

Declaration

func split(separator: Element, maxSplits: Int = default, omittingEmptySubsequences: Bool = default) -> [AnySequence<Element>]
Available when Element conforms to Equatable.

Parameters

separator

The element that should be split upon.

maxSplits

The maximum number of times to split the sequence, or one less than the number of subsequences to return. If maxSplits + 1 subsequences are returned, the last one is a suffix of the original sequence containing the remaining elements. maxSplits must be greater than or equal to zero. The default value is Int.max.

omittingEmptySubsequences

If false, an empty subsequence is returned in the result for each consecutive pair of separator elements in the sequence and for each instance of separator at the start or end of the sequence. If true, only nonempty subsequences are returned. The default value is true.

Return Value

An array of subsequences, split from this sequence’s elements.

Discussion

The resulting array consists of at most maxSplits + 1 subsequences. Elements that are used to split the sequence are not returned as part of any subsequence.

The following examples show the effects of the maxSplits and omittingEmptySubsequences parameters when splitting a string at each space character (” “). The first use of split returns each word that was originally separated by one or more spaces.

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " ")
          .map(String.init))
// Prints "["BLANCHE:", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

The second example passes 1 for the maxSplits parameter, so the original string is split just once, into two new strings.

print(line.split(separator: " ", maxSplits: 1)
          .map(String.init))
// Prints "["BLANCHE:", "  I don\'t want realism. I want magic!"]"

The final example passes false for the omittingEmptySubsequences parameter, so the returned array contains empty strings where spaces were repeated.

print(line.split(separator: " ", omittingEmptySubsequences: false)
          .map(String.init))
// Prints "["BLANCHE:", "", "", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

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