# StringProtocol Implementations ## Topics ### Structures [`struct UTF16View`](/documentation/Swift/String/UTF16View) A view of a string’s contents as a collection of UTF-16 code units. [`struct UTF8View`](/documentation/Swift/String/UTF8View) A view of a string’s contents as a collection of UTF-8 code units. [`struct UnicodeScalarView`](/documentation/Swift/String/UnicodeScalarView) A view of a string’s contents as a collection of Unicode scalar values. ### Operators [`static func != (Self, RHS) -> Bool`](/documentation/Swift/String/!=(_:_:)-frzf) [`static func == (Self, RHS) -> Bool`](/documentation/Swift/String/==(_:_:)-8kzxf) [`static func > (Self, RHS) -> Bool`](/documentation/Swift/String/_(_:_:)-6o7qv) [`static func < (Self, RHS) -> Bool`](/documentation/Swift/String/_(_:_:)-8d1wy) [`static func <= (Self, RHS) -> Bool`](/documentation/Swift/String/_=(_:_:)-5y22v) [`static func >= (Self, RHS) -> Bool`](/documentation/Swift/String/_=(_:_:)-nd86) ### Initializers [`init(cString: UnsafePointer)`](/documentation/Swift/String/init(cString:)-2p84k) Creates a new string by copying the null-terminated UTF-8 data referenced by the given pointer. [`init(decoding: C, as: Encoding.Type)`](/documentation/Swift/String/init(decoding:as:)) Creates a string from the given Unicode code units in the specified encoding. [`init(decodingCString: UnsafePointer, as: Encoding.Type)`](/documentation/Swift/String/init(decodingCString:as:)-8yowf) Creates a new string by copying the null-terminated sequence of code units referenced by the given pointer. ### Instance Properties [`var unicodeScalars: String.UnicodeScalarView`](/documentation/Swift/String/unicodeScalars) The string’s value represented as a collection of Unicode scalar values. [`var utf16: String.UTF16View`](/documentation/Swift/String/utf16) A UTF-16 encoding of `self`. [`var utf8: String.UTF8View`](/documentation/Swift/String/utf8) A UTF-8 encoding of `self`. ### Instance Methods [`func hasPrefix(String) -> Bool`](/documentation/Swift/String/hasPrefix(_:)) [`func hasSuffix(String) -> Bool`](/documentation/Swift/String/hasSuffix(_:)) [`func lowercased() -> String`](/documentation/Swift/String/lowercased()) Returns a lowercase version of the string. [`func uppercased() -> String`](/documentation/Swift/String/uppercased()) Returns an uppercase version of the string. [`func withCString((UnsafePointer) throws(E) -> Result) throws(E) -> Result`](/documentation/Swift/String/withCString(_:)) Calls the given closure with a pointer to the contents of the string, represented as a null-terminated sequence of UTF-8 code units. [`func withCString(encodedAs: TargetEncoding.Type, (UnsafePointer) throws(E) -> Result) throws(E) -> Result`](/documentation/Swift/String/withCString(encodedAs:_:)) Calls the given closure with a pointer to the contents of the string, represented as a null-terminated sequence of code units. --- 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)