Initializerswift 6.0.1Swift
init(_:radix:uppercase:)
Creates a string representing the given value in base 10, or some other specified base.
init<T>(_ value: T, radix: Int = 10, uppercase: Bool = false) where T : BinaryInteger Parameters
The following example converts the maximal Int value to a string and prints its length:
let max = String(Int.max)
print("\(max) has \(max.count) digits.")
// Prints "9223372036854775807 has 19 digits."Numerals greater than 9 are represented as Roman letters. These letters start with "A" if uppercase is true; otherwise, with "a".
let v = 999_999
print(String(v, radix: 2))
// Prints "11110100001000111111"
print(String(v, radix: 16))
// Prints "f423f"
print(String(v, radix: 16, uppercase: true))
// Prints "F423F"Other members in extension
Types
struct IndexA position of a character or code unit in a string.
struct Iteratorstruct UTF16ViewA view of a string’s contents as a collection of UTF-16 code units.
struct UTF8ViewA view of a string’s contents as a collection of UTF-8 code units.
struct UnicodeScalarViewA view of a string’s contents as a collection of Unicode scalar values.
Typealiases
typealias Elementtypealias SubSequencetypealias UnicodeScalarIndexThe index type for a string’s
unicodeScalarsview.
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typealias CharacterViewA view of a string’s contents as a collection of characters.
typealias IndexDistanceA type that represents the number of steps between two
String.Indexvalues, where one value is reachable from the other.
Type members
init() Creates an empty string.
init(String.UnicodeScalarView) Creates a string corresponding to the given collection of Unicode scalars.
init(String.UTF8View) Creates a string corresponding to the given sequence of UTF-8 code units.
init(String.UTF16View) Creates a string corresponding to the given sequence of UTF-16 code units.
init(Character) Creates a string containing the given character.
init?(Substring.UTF8View) Creates a String having the given content.
init?(Substring.UTF16View) Creates a String having the given content.
init(Substring.UnicodeScalarView) Creates a String having the given content.
init(Substring) Creates a new string from the given substring.
init(Unicode.Scalar) init<S>(S) Creates a new string containing the characters in the given sequence.
init<S>(S) Creates a new string containing the characters in the given sequence.
init<T>(T) Creates an instance from the description of a given
LosslessStringConvertibleinstance.init(cString: UnsafePointer<CChar>) Creates a new string by copying the null-terminated UTF-8 data referenced by the given pointer.
init(cString: UnsafePointer<UInt8>) Creates a new string by copying the null-terminated UTF-8 data referenced by the given pointer.
init?<T>(codingKey: T) init<C, Encoding>(decoding: C, as: Encoding.Type) init<Encoding>(decodingCString: UnsafePointer<Encoding.CodeUnit>, as: Encoding.Type) Creates a new string by copying the null-terminated sequence of code units referenced by the given pointer.
init<Subject>(describing: Subject) Creates a string representing the given value.
init<Subject>(describing: Subject) Creates a string representing the given value.
init<Subject>(describing: Subject) Creates a string representing the given value.
init<Subject>(describing: Subject) Creates a string representing the given value.
init(from: any Decoder) throws init<Subject>(reflecting: Subject) Creates a string with a detailed representation of the given value, suitable for debugging.
init(repeating: String, count: Int) Creates a new string representing the given string repeated the specified number of times.
init(repeating: Character, count: Int) Creates a string representing the given character repeated the specified number of times.
init(stringInterpolation: DefaultStringInterpolation) Creates a new instance from an interpolated string literal.
init(stringLiteral: String) Creates an instance initialized to the given string value.
init(unsafeUninitializedCapacity: Int, initializingUTF8With: (UnsafeMutableBufferPointer<UInt8>) throws -> Int) rethrows Creates a new string with the specified capacity in UTF-8 code units, and then calls the given closure with a buffer covering the string’s uninitialized memory.
init?<Encoding>(validating: some Sequence, as: Encoding.Type) Creates a new string by copying and validating the sequence of code units passed in, according to the specified encoding.
init?<Encoding>(validating: some Sequence<Int8>, as: Encoding.Type) Creates a new string by copying and validating the sequence of code units passed in, according to the specified encoding.
init?(validatingCString: UnsafePointer<CChar>) Creates a new string by copying and validating the null-terminated UTF-8 data referenced by the given pointer.
static func decodeCString<Encoding>(UnsafePointer<Encoding.CodeUnit>?, as: Encoding.Type, repairingInvalidCodeUnits: Bool) -> (result: String, repairsMade: Bool)? Creates a new string by copying the null-terminated data referenced by the given pointer using the specified encoding.
static func decodeCString<Encoding>([Encoding.CodeUnit], as: Encoding.Type, repairingInvalidCodeUnits: Bool) -> (result: String, repairsMade: Bool)? static func + (lhs: String, rhs: String) -> String static func += (lhs: inout String, rhs: String) static func < (lhs: String, rhs: String) -> Bool static func == (lhs: String, rhs: String) -> Bool static func ~= (lhs: String, rhs: Substring) -> Bool
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init(cString: String) init(cString: [CChar]) Creates a new string by copying the null-terminated UTF-8 data referenced by the given array.
init(cString: [UInt8]) Creates a new string by copying the null-terminated UTF-8 data referenced by the given array.
init(cString: inout CChar) init(cString: inout UInt8) init<Encoding>(decodingCString: String, as: Encoding.Type) init<Encoding>(decodingCString: inout Encoding.CodeUnit, as: Encoding.Type) init<Encoding>(decodingCString: [Encoding.CodeUnit], as: Encoding.Type) Creates a new string by copying the null-terminated sequence of code units referenced by the given array.
init?(validatingCString: String) init?(validatingCString: [CChar]) Creates a new string by copying and validating the null-terminated UTF-8 data referenced by the given array.
init?(validatingCString: inout CChar) init?(validatingUTF8: UnsafePointer<CChar>) Creates a new string by copying and validating the null-terminated UTF-8 data referenced by the given pointer.
init?(validatingUTF8: String) init?(validatingUTF8: [CChar]) Creates a new string by copying and validating the null-terminated UTF-8 data referenced by the given array.
init?(validatingUTF8: inout CChar) static func decodeCString<Encoding>(inout Encoding.CodeUnit, as: Encoding.Type, repairingInvalidCodeUnits: Bool) -> (result: String, repairsMade: Bool)? static func decodeCString<Encoding>(String, as: Encoding.Type, repairingInvalidCodeUnits: Bool) -> (result: String, repairsMade: Bool)?
Instance members
var codingKey: any CodingKeyvar count: IntThe number of characters in a string.
var customMirror: MirrorA mirror that reflects the
Stringinstance.var debugDescription: StringA representation of the string that is suitable for debugging.
var description: StringThe value of this string.
var endIndex: String.IndexA string’s “past the end” position—that is, the position one greater than the last valid subscript argument.
var isContiguousUTF8: BoolReturns whether this string is capable of providing access to validly-encoded UTF-8 contents in contiguous memory in O(1) time.
var isEmpty: BoolA Boolean value indicating whether a string has no characters.
var startIndex: String.IndexThe position of the first character in a nonempty string.
var unicodeScalars: String.UnicodeScalarViewThe string’s value represented as a collection of Unicode scalar values.
var utf16: String.UTF16ViewA UTF-16 encoding of
self.var utf8: String.UTF8ViewA UTF-8 encoding of
self.var utf8CString: ContiguousArray<CChar>A contiguously stored null-terminated UTF-8 representation of the string.
subscript(String.Index) -> Character Accesses the character at the given position.
subscript(Range<String.Index>) -> Substring func append(Character) Appends the given character to the string.
func append(String) Appends the given string to this string.
func append(contentsOf: String) func append(contentsOf: Substring) func append<S>(contentsOf: S) Appends the characters in the given sequence to the string.
func distance(from: String.Index, to: String.Index) -> Int Returns the distance between two indices.
func encode(to: any Encoder) throws Encodes this value into the given encoder.
func hasPrefix(String) -> Bool func hasSuffix(String) -> Bool func hash(into: inout Hasher) Hashes the essential components of this value by feeding them into the given hasher.
func index(String.Index, offsetBy: Int) -> String.Index Returns an index that is the specified distance from the given index.
func index(String.Index, offsetBy: Int, limitedBy: String.Index) -> String.Index? Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.
func index(after: String.Index) -> String.Index Returns the position immediately after the given index.
func index(before: String.Index) -> String.Index func insert(Character, at: String.Index) Inserts a new character at the specified position.
func insert<S>(contentsOf: S, at: String.Index) Inserts a collection of characters at the specified position.
func lowercased() -> String Returns a lowercase version of the string.
func makeContiguousUTF8() If this string is not contiguous, make it so. If this mutates the string, it will invalidate any pre-existing indices.
func makeIterator() -> String.Iterator func max<T>(T, T) -> T func min<T>(T, T) -> T func remove(at: String.Index) -> Character Removes and returns the character at the specified position.
func removeAll(keepingCapacity: Bool) Replaces this string with the empty string.
func removeSubrange(Range<String.Index>) Removes the characters in the given range.
func replaceSubrange<C>(Range<String.Index>, with: C) Replaces the text within the specified bounds with the given characters.
func reserveCapacity(Int) Reserves enough space in the string’s underlying storage to store the specified number of ASCII characters.
func uppercased() -> String Returns an uppercase version of the string.
func withCString<Result>((UnsafePointer<Int8>) throws -> Result) rethrows -> Result func withCString<Result, TargetEncoding>(encodedAs: TargetEncoding.Type, (UnsafePointer<TargetEncoding.CodeUnit>) throws -> Result) rethrows -> Result func withUTF8<R>((UnsafeBufferPointer<UInt8>) throws -> R) rethrows -> R Runs
bodyover the content of this string in contiguous memory. If this string is not contiguous, this will first make it contiguous, which will also speed up subsequent access. If this mutates the string, it will invalidate any pre-existing indices.func write(String) Appends the given string to this string.
func write<Target>(to: inout Target) Writes the string into the given output stream.
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var characters: StringA view of the string’s contents as a collection of characters.
var customPlaygroundQuickLook: _PlaygroundQuickLookA custom playground Quick Look for the
Stringinstance.func withMutableCharacters<R>((inout String) -> R) -> R Applies the given closure to a mutable view of the string’s characters.