Swift的筆記和參考

好久沒來了，趁着新語言Swift發布，繼續鑽研中！

Create Class 創建類 （重載效果）

// Create Class 創建類
class MyClass {

    // Properties 成員變量
    
    init() {
        // Constructor 構造函數
    }
    
    // Method 成員方法
    func doIt() {
        println("doIt")
    }
    
    func doIt() -> Int {
        return 0
    }
    
    func doIt(a:Int) -> Int {
        return a
    }
    
    func doIt(a:Int, b:Int) -> Int {
        return a + b
    }
    
    func doIt() -> String {
        return ""
    }
    
    func doIt(a:String) -> String {
        return a
    }
    
    func doIt(a:String, b:String) -> String {
        return a + b
    }

}

// Create / Using an Instance 創建 / 使用 一個實例
var a = MyClass()
a.doIt("Wang ", b: "Zhipeng")

 

Enums 枚舉

// Enums 枚舉
enum ComcSoftType: Int {
    
    case DevelopmentEngineer = 1
    
    case TestEngineer = 2
    
}

var myType = ComcSoftType.DevelopmentEngineer

 

Declaring Variables 變量的聲明 （可選變量）

// Declaring Variables 變量的聲明
var mutableDouble:Double = 1.0
mutableDouble = 2.0

let constantDouble:Double = 1.0
//constantDouble = 2.0 Error 錯誤

var autoDouble = 1.0

// Optional Value 可選變量 （新機制）
var optionDouble:Double? //此刻 optionDouble 根本沒有分配內存，對其取地址: &optionDouble 為NULL
optionDouble = 1.0 //這時候開始 optionDouble 才會開始分配內存

if let defineDouble = optionDouble {
    println("已經分配內存")
}
else {
    println("沒有分配內存")
}

 

Control Flow 控制流

// Control Flow 控制流
var condition = true
if condition {
    println("正確")
}
else {
    println("錯誤")
}


var val = "Four"
switch val {
    case "One":
        "One"
    case "Two", "Three":
        "Two, Three"
    default:
        "default"
}


// omits upper value, use ... to include  省略了上限值，使用 ... 包括
for i in 0..3 {
    println("i = \(i)")
}

for var j = 0; j < 3; ++j {
    println("j = \(j)")
}

// While
var n = 2
while n < 100 {
    n = n * 2
}
println(n)

var m = 2
do {
    m = m * 2
} while m < 100
println(m)

 

String Quick Examples 字符串的例子

// String Quick Examples 字符串的例子
var firstName = "Zhipeng"
var lastName = "Wang"
var helloString = "Hello, \(lastName) \(firstName)"

var tipString = "2499"
var tipInt = tipString.toInt()

extension Double {
    init (string:String) {
        self = Double(string.bridgeToObjectiveC().doubleValue)
    }
}
tipString = "24.99"
var tipDouble = Double(string:tipString)

 

Array Quick Examples 數組的例子

// Array Quick Examples 數組的例子
var person1 = "One"
var person2 = "Two"
var array:String[] = [person1, person2]
array += "Three"
for person in array {
    println("person: \(person)")
}
var personTwo = array[1]
println("personTwo: \(personTwo)")

 

Dictionary Quick Examples 字典的例子 （泛型效果）

// Dictionary Quick Examples 字典的例子
var dic:Dictionary<String, String> = ["One": "1",
                                     "Two": "2",
                                     "Three": "3"]
dic["Three"] = "4" // Update Three
dic["One"] = nil // Delete One
for(key, value) in dic {
    println("key: \(key), value: \(value)")
}

 

Function 函數

// Function 函數
func getPirces() -> (Double, Double, Double) {
    return (1.1, 1.2, 1.3) // tuple 元組
}
// 取出元組
var (one, two, three) = getPirces()
println("One = \(one), Two = \(two), Three = \(three)")

func getSum(numbers:Int...) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}
getSum()
getSum(1, 3, 5, 7, 9)

 

函數嵌套

// 函數嵌套
func nestedFunction() -> Int {
    var x = 0
    //
    func add() {
        x += 1
    }
    //
    add()
    return x
}

 

函數傳遞

// 函數傳遞
func makeIncrementer() -> (Int -> Int) {
    func addOne(number:Int) -> Int {
        return number + 1
    }
    return addOne
}

var increment = makeIncrementer()
increment(1)

func makeIncrementer2() -> ((String, String) -> String) {
    func and(a:String, b:String) -> String {
        return a + b
    }
    return and
}
var increment2 = makeIncrementer2()
increment2("Wang ", "zhieng")

func lessThanOne(number:Int) -> Bool {
    return number < 1
}
func makeIncrementer3(list:Int[], condition:Int -> Bool) -> Bool {
    for number in list {
        if condition(number) {
            return true
        }
    }
    return false
}
makeIncrementer3([1,2,3,4,5], lessThanOne)

 

 Extends 繼承 (多態效果)

// Extends 繼承 (多態效果)
println("======================= Extends 繼承")
class People {
    // Eat 吃
    func eat() {
        println("吃")
    }
    // Sleep 睡
    func sleep() {
        println("睡")
    }
    // Work 工作
    func work() {
        println("工作")
    }
    // Said 說
    func said() {
        println("我是人")
    }
}

class Chinese:People {
    // Said 說
    override func said() {
        println("我是中國人")
    }
}

class Americans:People {
    // Said 說
    override func said() {
        println("我是美國人")
    }
}

class Alien {
    // Eat 吃
    func unknown() {
        println("外星人")
    }
}

// 不支持多繼承
//class futureGenerations:Chinese, Americans { // Multiple inheritance from classes 'Chinese' and 'Americans'
//    // Said 說
//    override func said() {
//        println("我是中國人和美國人的后代")
//    }
//}

// 多態 必要條件:1.繼承 2.重寫 3.父類引用指向子類對象
var people = People()
people.said()
people = Chinese()
people.said()
people = Americans()
people.said()
//people = Alien() Error 'Alien' is not convertible to 'People'
//people.said()

var chinese = Chinese()
chinese.said()

var americans = Americans()
americans.said()