[Swift] Strings and Characters

let someString = "Hello, World!"

let multiLineString = """ The White Rabbit put on his spectacles. "Where shall I begin, please your Majesty?" he asked. "Begin at the beginning," the King said gravely, "and go on till you come to the end; then stop." """

let multiLineString = """ The White Rabbit put on his spectacles. "Where shall I begin, \ please your Majesty?" he asked. "Begin at the beginning," the King said gravely, "and go on \ till you come to the end; then stop." """

let multiLineString = """ The White Rabbit put on his spectacles. "Where shall I begin, please your Majesty?" he asked. "Begin at the beginning," the King said gravely, "and go on till you come to the end; then stop." """

let specialCharacters = "\0 \\ \t \n \r \" \'" print(specialCharacters)

let specialCharacters = ##"\n \0 \r \t \\ \" \' \##u{1F496}"## print(specialCharacters)

var emptyString = "" // empty string literal var anotherEmptyString = String() // initializer syntax

if emptyString.isEmpty { print("Nothing to see here") } // Prints "Nothing to see here"

let greeting = "Guten Tag!" greeting[greeting.startIndex] // G greeting[greeting.endIndex] // error

greeting[greeting.index(before: greeting.endIndex)] // !

let index = greeting.index(greeting.startIndex, offsetBy: 7) greeting[index] // a

for index in greeting.indices { print("\(greeting[index]) ", terminator: "") }

var welcome = "hello" welcome.insert("!", at: welcome.endIndex) // hello! welcome.remove(at: welcome.index(before: welcome.endIndex)) // hello

var welcome = "hello" welcome.insert(contentsOf: " there", at: welcome.endIndex) // hello there let range = welcome.index(welcome.endIndex, offsetBy: -6)..<welcome.endIndex welcome.removeSubrange(range) // hello

let greeting = "Hello, world!" let index = greeting.firstIndex(of: ",") ?? greeting.endIndex let beginning = greeting[..<index] // Hello

let greeting = "Hello, world!" let index = greeting.firstIndex(of: ",") ?? greeting.endIndex let beginning = greeting[..<index] let newString = String(beginning)

let multiplier = 3 let message = "\(multiplier) times 2.5 is \(Double(multiplier) * 2.5)" // 3 times 2.5 is 7.5

print(#"6 times 7 is \#(6 * 7)."#) // 6 times 7 is 42.

for character in "Dog!🐶" { print(character) } // D // o // g // ! // 🐶

let exclamationMark: Character = "!"

let catCharacters: [Character] = ["C", "a", "t", "!", "🐱"] let catString = String(catCharacters) print(catString)

let string1 = "hello" let string2 = " there" var welcome = string1 + string2 // hello there var instruction = "look over" instruction += string2 // look over there

let exclamationMark: Character = "!" welcome.append(exclamationMark) // hello there!

let goodStart = """ one two """ let end = """ three """ print(goodStart + end) // one // two // three

let eAcute: Character = "\u{E9}" // é let combinedEAcute: Character = "\u{65}\u{301}" // e followed by ́

let unusualMenagerie = "Koala 🐨, Snail 🐌, Penguin 🐧, Dromedary 🐪" print("unusualMenagerie has \(unusualMenagerie.count) characters") // unusualMenagerie has 40 characters

var word = "cafe" print("the number of characters in \(word) is \(word.count)") // the number of characters in cafe is 4 word += "\u{301}" // COMBINING ACUTE ACCENT, U+0301 print("the number of characters in \(word) is \(word.count)") // the number of characters in café is 4

// Voulez-vous un café? let eAcuteQuestion = "Voulez-vous un caf\u{E9}?" // Voulez-vous un café? let combinedEAcuteQuestion = "Voulez-vous un caf\u{65}\u{301}?" if eAcuteQuestion == combinedEAcuteQuestion { print("These two strings are considered equal") } // These two strings are considered equal

let latinCapitalLetterA: Character = "\u{41}" let cyrillicCapitalLetterA: Character = "\u{0410}" if latinCapitalLetterA != cyrillicCapitalLetterA { print("These two characters aren't equivalent.") } // Prints "These two characters aren't equivalent."

let romeoAndJuliet = [ "Act 1 Scene 1: Verona, A public place", "Act 1 Scene 2: Capulet's mansion", "Act 2 Scene 1: Outside Capulet's mansion", "Act 2 Scene 2: Capulet's orchard", "Act 2 Scene 3: Outside Friar Lawrence's cell", ]

var act1SceneCount = 0 for scene in romeoAndJuliet { if scene.hasPrefix("Act 1 ") { act1SceneCount += 1 } } print("There are \(act1SceneCount) scenes in Act 1") // There are 2 scenes in Act 1

var mansionCount = 0 var cellCount = 0 for scene in romeoAndJuliet { if scene.hasSuffix("Capulet's mansion") { mansionCount += 1 } else if scene.hasSuffix("Friar Lawrence's cell") { cellCount += 1 } } print("\(mansionCount) mansion scenes; \(cellCount) cell scenes") // 2 mansion scenes; 1 cell scenes

let dogString = "Dog‼🐶" for codeUnit in dogString.utf8 { print("\(codeUnit) ", terminator: "") } print("") // 68 111 103 226 128 188 240 159 144 182

for codeUnit in dogString.utf16 { print("\(codeUnit) ", terminator: "") } print("") // 68 111 103 8252 55357 56374

for scalar in dogString.unicodeScalars { print("\(scalar.value) ", terminator: "") } print("") // 68 111 103 8252 128054

for scalar in dogString.unicodeScalars { print("\(scalar) ", terminator: "") } // D o g ‼ 🐶