# StaticString A string type designed to represent text that is known at compile time. ``` @frozen struct StaticString ``` ## Overview Instances of the `StaticString` type are immutable. `StaticString` provides only low-level access to its contents, unlike Swift’s more commonly used `String` type. A static string can use either of the following as its storage: - a pointer to a null-terminated sequence of UTF-8 code units: ``` let emoji: StaticString = "\u{1F600}" emoji.hasPointerRepresentation //-> true emoji.isASCII //-> false emoji.unicodeScalar //-> Fatal error! emoji.utf8CodeUnitCount //-> 4 emoji.utf8Start[0] //-> 0xF0 emoji.utf8Start[1] //-> 0x9F emoji.utf8Start[2] //-> 0x98 emoji.utf8Start[3] //-> 0x80 emoji.utf8Start[4] //-> 0x00 ``` - a single Unicode scalar value, under very limited circumstances: ``` struct MyStaticScalar: ExpressibleByUnicodeScalarLiteral { typealias UnicodeScalarLiteralType = StaticString let value: StaticString init(unicodeScalarLiteral value: StaticString) { self.value = value } } let emoji: StaticString = MyStaticScalar("\u{1F600}").value emoji.hasPointerRepresentation //-> false emoji.isASCII //-> false emoji.unicodeScalar.value //-> 0x1F600 emoji.utf8CodeUnitCount //-> Fatal error! emoji.utf8Start //-> Fatal error! ``` You can use the `withUTF8Buffer(_:)` method to access a static string’s contents, regardless of which representation the static string uses. ``` emoji.withUTF8Buffer { utf8 in utf8.count //-> 4 utf8[0] //-> 0xF0 utf8[1] //-> 0x9F utf8[2] //-> 0x98 utf8[3] //-> 0x80 utf8[4] //-> Fatal error! } ``` ## Relationships ### Conforms To [`Sendable`](/documentation/Swift/Sendable) [`ExpressibleByStringLiteral`](/documentation/Swift/ExpressibleByStringLiteral) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`Escapable`](/documentation/Swift/Escapable) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`ExpressibleByUnicodeScalarLiteral`](/documentation/Swift/ExpressibleByUnicodeScalarLiteral) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable) [`ExpressibleByExtendedGraphemeClusterLiteral`](/documentation/Swift/ExpressibleByExtendedGraphemeClusterLiteral) [`Copyable`](/documentation/Swift/Copyable) [`CustomReflectable`](/documentation/Swift/CustomReflectable) --- 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)