# UTF8Span.CharacterIterator Iterate the `Character` contents of a `UTF8Span`. ``` struct CharacterIterator ``` ## Overview ``` func countCharacters(_ string: borrowing String) { var iterator = string.utf8Span.makeCharacterIterator() var count = 0 while let character = iterator.next() { count += 1 print("Character \(count): \(character)") } print("Total: \(count) characters") } let string = "لاهور" countCharacters(string) // Prints "Character 1: ل" // Prints "Character 2: ا" // Prints "Character 3: ه" // Prints "Character 4: و" // Prints "Character 5: ر" // Prints "Total: 5 characters" ``` ## Topics ### Initializers [`init(UTF8Span)`](/documentation/Swift/UTF8Span/CharacterIterator/init(_:)) ### Instance Properties [`let codeUnits: UTF8Span`](/documentation/Swift/UTF8Span/CharacterIterator/codeUnits) [`var currentCodeUnitOffset: Int`](/documentation/Swift/UTF8Span/CharacterIterator/currentCodeUnitOffset) The byte offset of the start of the next `Character`. This is always scalar-aligned. It is always `Character`-aligned relative to the last call to `reset` (or the start of the span if not called). ### Instance Methods [`func next() -> Character?`](/documentation/Swift/UTF8Span/CharacterIterator/next()) Return the `Character` starting at `currentCodeUnitOffset`. After the function returns, `currentCodeUnitOffset` holds the position at the end of the `Character`, which is also the start of the next `Character`. [`func prefix() -> UTF8Span`](/documentation/Swift/UTF8Span/CharacterIterator/prefix()) Returns the UTF8Span containing all the content up to the iterator’s current position. [`func previous() -> Character?`](/documentation/Swift/UTF8Span/CharacterIterator/previous()) Return the `Character` ending at `currentCodeUnitOffset`. After the function returns, `currentCodeUnitOffset` holds the position at the start of the returned `Character`, which is also the end of the previous `Character`. [`func reset(roundingBackwardsFrom: Int)`](/documentation/Swift/UTF8Span/CharacterIterator/reset(roundingBackwardsFrom:)) Reset to the nearest character-aligned position `<= i`. [`func reset(roundingForwardsFrom: Int)`](/documentation/Swift/UTF8Span/CharacterIterator/reset(roundingForwardsFrom:)) Reset to the nearest character-aligned position `>= i`. [`func reset(toUnchecked: Int)`](/documentation/Swift/UTF8Span/CharacterIterator/reset(toUnchecked:)) Reset this iterator to `codeUnitOffset`, skipping *all* safety checks. [`func skipBack() -> Int`](/documentation/Swift/UTF8Span/CharacterIterator/skipBack()) Move `currentCodeUnitOffset` to the start of the previous `Character`, without constructing it. [`func skipBack(by: Int) -> Int`](/documentation/Swift/UTF8Span/CharacterIterator/skipBack(by:)) Move `currentCodeUnitOffset` to the start of the previous `n` `Character`s, without constructing them. [`func skipForward() -> Int`](/documentation/Swift/UTF8Span/CharacterIterator/skipForward()) Advance `currentCodeUnitOffset` to the end of the current `Character`, without constructing it. [`func skipForward(by: Int) -> Int`](/documentation/Swift/UTF8Span/CharacterIterator/skipForward(by:)) Advance `currentCodeUnitOffset` to the end of `n` `Characters`, without constructing them. [`func suffix() -> UTF8Span`](/documentation/Swift/UTF8Span/CharacterIterator/suffix()) Returns the UTF8Span containing all the content after the iterator’s current position. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)