類別＆結構＆列舉　Class & Structure & Enumeration

介紹

• class 架構
• 標注型別
• 傳遞參數值
• 加入條件
• 類別繼承
• 插入函式
• ＝＝＝＆！＝＝
• struct 架構
• enum 架構
• enum ＆ switch
• 關連值（associated value）
• 原始值（rawValue）

class 架構

class (名稱) {
}

class data {
    var text1 = "learning swift"
    var text2 = " is good."
}

var DATA = data()
print(DATA.text1 + DATA.text2)

• 輸出結果

  learning swift is good.
  

標注型別

class data {
    var text1: String
    var text2: String
    init() {
        self.text1 = "learning swift"
        self.text2 = " is good."
    }
}

var DATA = data()
print(DATA.text1 + DATA.text2)

• 輸出結果

  learning swift is good.
  

傳遞參數值

class data {
    var text1: String
    var text2: String
    init(text1: String, text2: String) {
        self.text1 = text1
        self.text2 = text2
    }
}

var DATA = data(text1: "learning swift", text2: " is good.")
print(DATA.text1 + DATA.text2)

• 輸出結果

  learning swift is good.
  

加入條件

class data {
    var text1: String
    var text2: String
    init(text1: String, text2: String) {
        self.text1 = text1
        self.text2 = text2
        if text1.isEmpty || text2.isEmpty {
            self.text1 = "nothing"
            self.text2 = ""
        }
    }
}

var DATA = data(text1: "learning swift", text2: " is good.")
var DATA2 = data(text1: "", text2: "")
print(DATA.text1 + DATA.text2)
print(DATA2.text1 + DATA2.text2)

• 輸出結果

  learning swift is good.
  nothing
  

類別繼承

class data {
    var text1: String
    var text2: String
    init(text1: String, text2: String) {
        self.text1 = text1
        self.text2 = text2
        if text1.isEmpty || text2.isEmpty {
            self.text1 = "nothing"
            self.text2 = ""
        }
    }
}
class data2: data {
}

let DATA = data2(text1: "learning swift", text2: " is good.")
print(DATA.text1 + DATA.text2)

• 輸出結果

  learning swift is good.
  

插入函式

class data {
    var text1: String = "learning swift"
    var text2: String = " is good."
    func PRINT() {
        print(text1 + text2)
    }
}

var DATA = data()
    DATA.PRINT()

• 輸出結果

  learning swift is good.
  

＝＝＝＆！＝＝

class data {
    var text1: String
    var text2: String
    init() {
        self.text1 = "learning swift"
        self.text2 = " is good."
    }
}

var DATA1 = data()
var DATA2 = data()
var DATA3 = DATA1
var text1 = DATA1 === DATA2 ? "it is same class" : "it is different class"
print(text1)
var text2 = DATA3 === DATA1 ? "it is same class" : "it is different class"
print(text2)

• 輸出結果

  it is different class
  it is same class
  

struct 架構

struct (名稱) {
}

struct data {
    var text1 = "learning swift"
    var text2 = " is good."
}

var DATA = data()
print(DATA.text1 + DATA.text2)

• 輸出結果

  learning swift is good.
  

  • 與 class 用法相近，但不具繼承功能。

enum 架構

    enum (名稱) {
    case (值)
}

enum number: String {
    case one = "1"
    case two = "2"
    case three = "3"
}

var data = number.one
var data2: number = .two
print(data.rawValue)
print(data2.rawValue)

• 輸出結果

  1
  2
  

enum ＆ switch

enum number: String {
    case one
    case two
    case three
}

let data = number.one
switch data {
    case .one:
        print("one")
    case .two:
        print("two")
    case .three:
        print("three")
    default:
        break
}

• 輸出結果

  one
  

關連值（associated value）

enum number {
    case one(String)
    case two(String)
    case three(String)
}

let data = number.one("1234567890")
switch data {
    case .one(let text):
        print("one, \(text)")
    case .two(let text):
        print("two, \(text)")
    case .three(let text):
        print("three, \(text)")
    default:
        break
}

• 輸出結果

  one, 1234567890
  

原始值（rawValue）

enum number: String {
    case one = "1"
    case two = "2"
    case three = "3"
}

let data = number.one.rawValue
print(data)

• 輸出結果

  1