3. 문자와 문자열 Strings and Characters Swift 공식 문서 - 판나의 노트

//: Playground - noun: a place where people can play

import UIKit

// #       
//         ，  String  。String         ，        。
let quotation = """
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 threeDoubleQuotes = """
    Escaping the first quote \"""

        Escaping all three quotes \"\"\"

    """
print(threeDoubleQuotes)

// #          
// trick:       
var emptyString = ""
if emptyString.isEmpty {
    print("Nothing to see here")
}

// #       

// #        
// trick:        ， c   a、b a、b     
var a = "wanna"
var b = "gonna"
var c = [a, b]

// #     
// for-in loop
for character in "Dog!" {
    print(character)
}
//         ，           
let exclamationMark: Character = "!"
// String        Character                     ，    String    init
let catCharacters: [Character] = ["C", "a", "t", "!", ""]
let catString = String(catCharacters)

// #         
var welcome = ""
welcome += "Bonjour"
welcome.append(exclamationMark)

// #      

// # Unicode
// Unicode              、            。     Unicode         
//               
"\0"//    
"\\"//    
"\t"//      
"
"//    ，n  newline
"\r"//    ，r  return，     mac       ???
"\""//    
"\'"//    
print("hao\rde")
"\u{1F443}" //  Unicode   
//       
let precomposed: Character = "\u{D55C}" // 한
let decomposed: Character = "\u{1112}\u{1161}\u{11AB}" // ᄒ, ᅡ, ᆫ
let enclosedEAcute: Character = "\u{E9}\u{20DD}" //     
//         Unicode                Character 
let regionalIndicatorForUS: Character = "\u{1F1FA}\u{1F1F8}"

// #     
//   .count       Unicode           ，      Unicode   
var word = "cafe"
word.count
word += "\u{301}" // combined
word.count

// #         
// String  [Character],         ,   index。                         ,                    
// endIndex    String           ,          .   String  ，  startIndex  endIndex  。
var greeting = "Bonjour!"
greeting[greeting.startIndex]
greeting[greeting.index(after: greeting.startIndex)]
greeting[greeting.index(before: greeting.endIndex)]
//  offsetBy     
greeting[greeting.index(greeting.startIndex, offsetBy: 1)]
// .indices        index( endIndex)
for index in greeting.indices {
    print("\(greeting[index])", terminator: "")
}
//          Indexable          startIndex   endIndex      index(before:) ， index(after:)   index(_:offsetBy:)   。         String ，         Array ， Dictionary   Set 。
var test = [1, 2, 3]
test[test.startIndex]
test[0]
//   ,remove(at:)     Character
greeting.remove(at: greeting.index(before: greeting.endIndex))
greeting.removeSubrange(greeting.startIndex..