# Sequence Implementations ## Topics ### Instance Properties [`var lazy: LazySequence`](/documentation/Swift/Int64/Words-swift.struct/lazy) A sequence containing the same elements as this sequence, but on which some operations, such as `map` and `filter`, are implemented lazily. ### Instance Methods [`func allSatisfy((Self.Element) throws -> Bool) rethrows -> Bool`](/documentation/Swift/Int64/Words-swift.struct/allSatisfy(_:)) Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate. [`func compactMap((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]`](/documentation/Swift/Int64/Words-swift.struct/compactMap(_:)) Returns an array containing the non-`nil` results of calling the given transformation with each element of this sequence. [`func contains(Self.Element) -> Bool`](/documentation/Swift/Int64/Words-swift.struct/contains(_:)) Returns a Boolean value indicating whether the sequence contains the given element. [`func contains(where: (Self.Element) throws -> Bool) rethrows -> Bool`](/documentation/Swift/Int64/Words-swift.struct/contains(where:)) Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate. [`func count(where: (Self.Element) throws(E) -> Bool) throws(E) -> Int`](/documentation/Swift/Int64/Words-swift.struct/count(where:)) Returns the number of elements in the sequence that satisfy the given predicate. [`func elementsEqual(OtherSequence) -> Bool`](/documentation/Swift/Int64/Words-swift.struct/elementsEqual(_:)) Returns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order. [`func elementsEqual(OtherSequence, by: (Self.Element, OtherSequence.Element) throws -> Bool) rethrows -> Bool`](/documentation/Swift/Int64/Words-swift.struct/elementsEqual(_:by:)) Returns a Boolean value indicating whether this sequence and another sequence contain equivalent elements in the same order, using the given predicate as the equivalence test. [`func enumerated() -> EnumeratedSequence`](/documentation/Swift/Int64/Words-swift.struct/enumerated()) Returns a sequence of pairs (*n*, *x*), where *n* represents a consecutive integer starting at zero and *x* represents an element of the sequence. [`func filter((Self.Element) throws(E) -> Bool) throws(E) -> [Self.Element]`](/documentation/Swift/Int64/Words-swift.struct/filter(_:)) Returns an array containing, in order, the elements of the sequence that satisfy the given predicate. [`func first(where: (Self.Element) throws -> Bool) rethrows -> Self.Element?`](/documentation/Swift/Int64/Words-swift.struct/first(where:)) Returns the first element of the sequence that satisfies the given predicate. [`func flatMap((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]`](/documentation/Swift/Int64/Words-swift.struct/flatMap(_:)-5ogxw) [`func flatMap((Self.Element) throws -> SegmentOfResult) rethrows -> [SegmentOfResult.Element]`](/documentation/Swift/Int64/Words-swift.struct/flatMap(_:)-8dp2z) Returns an array containing the concatenated results of calling the given transformation with each element of this sequence. [`func forEach((Self.Element) throws -> Void) rethrows`](/documentation/Swift/Int64/Words-swift.struct/forEach(_:)) Calls the given closure on each element in the sequence in the same order as a `for`-`in` loop. [`func lexicographicallyPrecedes(OtherSequence) -> Bool`](/documentation/Swift/Int64/Words-swift.struct/lexicographicallyPrecedes(_:)) Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the less-than operator (`<`) to compare elements. [`func lexicographicallyPrecedes(OtherSequence, by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Bool`](/documentation/Swift/Int64/Words-swift.struct/lexicographicallyPrecedes(_:by:)) Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements. [`func map((Self.Element) throws(E) -> T) throws(E) -> [T]`](/documentation/Swift/Int64/Words-swift.struct/map(_:)-5qll5) Returns an array containing the results of mapping the given closure over the sequence’s elements. [`func max() -> Self.Element?`](/documentation/Swift/Int64/Words-swift.struct/max()) Returns the maximum element in the sequence. [`func max(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element?`](/documentation/Swift/Int64/Words-swift.struct/max(by:)) Returns the maximum element in the sequence, using the given predicate as the comparison between elements. [`func min() -> Self.Element?`](/documentation/Swift/Int64/Words-swift.struct/min()) Returns the minimum element in the sequence. [`func min(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element?`](/documentation/Swift/Int64/Words-swift.struct/min(by:)) Returns the minimum element in the sequence, using the given predicate as the comparison between elements. [`func reduce(Result, (Result, Self.Element) throws -> Result) rethrows -> Result`](/documentation/Swift/Int64/Words-swift.struct/reduce(_:_:)) Returns the result of combining the elements of the sequence using the given closure. [`func reduce(into: Result, (inout Result, Self.Element) throws -> ()) rethrows -> Result`](/documentation/Swift/Int64/Words-swift.struct/reduce(into:_:)) Returns the result of combining the elements of the sequence using the given closure. [`func shuffled() -> [Self.Element]`](/documentation/Swift/Int64/Words-swift.struct/shuffled()) Returns the elements of the sequence, shuffled. [`func shuffled(using: inout T) -> [Self.Element]`](/documentation/Swift/Int64/Words-swift.struct/shuffled(using:)) Returns the elements of the sequence, shuffled using the given generator as a source for randomness. [`func sorted() -> [Self.Element]`](/documentation/Swift/Int64/Words-swift.struct/sorted()) Returns the elements of the sequence, sorted. [`func sorted(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> [Self.Element]`](/documentation/Swift/Int64/Words-swift.struct/sorted(by:)) Returns the elements of the sequence, sorted using the given predicate as the comparison between elements. [`func starts(with: PossiblePrefix) -> Bool`](/documentation/Swift/Int64/Words-swift.struct/starts(with:)) Returns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in another sequence. [`func starts(with: PossiblePrefix, by: (Self.Element, PossiblePrefix.Element) throws -> Bool) rethrows -> Bool`](/documentation/Swift/Int64/Words-swift.struct/starts(with:by:)) Returns a Boolean value indicating whether the initial elements of the sequence are equivalent to the elements in another sequence, using the given predicate as the equivalence test. [`func withContiguousStorageIfAvailable((UnsafeBufferPointer) throws -> R) rethrows -> R?`](/documentation/Swift/Int64/Words-swift.struct/withContiguousStorageIfAvailable(_:)) Executes a closure on the sequence’s contiguous storage. --- Copyright © 2026 Apple Inc. 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