Swift编程注释小记1(变量，函数，类)

--阅读The Swift Progrmaing Language 

--Swift 中的self 参考了Python, 也有函数式编程的影子，

import Foundation//Varibal 变量和定义篇 ===============================================println("Hello, World!")//var 表示变量， let表示常量,所有的数据类型的的首字母是需要大写的var myVariable = 42myVariable = 50let myConstant = 42let explicitDouble: Double = 70let lablel = "The width is "let width = 40let widthLable = lablel + String(width)println(widthLable)let apples = 3let oranges = 5let appleSummary = "I have \(apples) apples."//两个整数相加时，任意一个不能为浮点数let fruitSummary = "I have \(apples + oranges) pieces of fruit."//打印语句println(appleSummary)println(fruitSummary)//array and dictionaryvar shoppingList = ["catfish", "water","tulips","blue paint"]shoppingList[1] = "bottle of water"var occpations = [    "Malcolm":"Captain",    "Kaylee":"Mechanic",]occpations["Jayne"] = "Public Relations"println(shoppingList)println(occpations)//create empty array and dictionarylet emptyArray = String[]()let emptyDictionary = Dictionary<String, Float>()//for loop  statment must be bool typelet individualScores = [75,43, 103,87,12]var tempScore = 0for score in individualScores{    if score  > 50    {        tempScore += 3    }    else    {        tempScore += 1    }}println(tempScore)//for and let together usevar optionalString:String? = "Hello"optionalString == nilvar optionalName : String? = "John Appleaseed"var greeting = "Hello"/* if name is nil the code int braces is skipped*/if let name = optionalName{    greeting = "Hello ,\(name)"}//switch...case//must need add default case and is no need to explicitly breaklet vegetable = "red pepper"switch vegetable{case "celery":    let vegetableComment = "Add some raisions and make ants on a log"case "cucumber", "watercress":    let vegetableComment = "That would make a good tea sandwich"case let x where x.hasSuffix("pepper"):    let vegetable = "It it a spicy \(x)?"default:    let vegetableComment = "Everything tasts good is soup"}//for in providing a pair of name to user for key-value pairlet interestingNumbers = [    "Prime" : [2,4,5,7,11,13],    "Fibonacci" : [1,1,2,3,5,8],    "Squear" : [1,4,5,16,25],]var largest = 0for (kind, numbers) in interestingNumbers {    for number in numbers {        if number > largest{            largest = number        }    }}println("largest = \(largest)")//whilevar n = 2while n < 100 {    n = n * 2}var m = 2do {    m = m * 2} while m < 100println("n = \(n), m = \(m).")//for i in 0..3  I think don't using this statment ,on method resoulation one Problem//Function 篇 ====================================================//func and closures,one return value//“Use -> to separate the parameter names and types from the function’s return type.”func greet(name:String,day:String) -> String{    return "Hello \(name), today is \(day)."}let Return:String = greet("Bob", "Tues")println("Return = \(Return)")//func and closures ,Use a tuple to return multiple values from a function,rember is a tuplefunc getGasPrices() -> (Double, Double, Double){    return (3.58,4.23,45.234)}let MultipleReturn = getGasPrices()println("MultipleReturn = \(MultipleReturn)")// func and closures, functions can nested,就是可以在一个函数中定义多个函数，低层次中的函数可以使用上层次中的变量。func returnFifteen() -> Int {    var y = 10        func add() {        y += 5    }    add()    return y}let result : Int  = returnFifteen()println("result = \(result)")//func and closures, first-class-type //意思就是一个函数可以当成值返回，so coolfunc makeIncrementer() -> (Int -> Int) {    func addOne(number :Int) -> Int {        return 1 + number    }    return addOne}var increment = makeIncrementer()println(increment(7))println("---------------------------------")//func and closures, A function can tak another function as one of ites argument//一个函数可以作为一个参数其它函数使用func hasAnyMatches(list:Int[], condition: Int -> Bool) -> Bool{    for item in list {        if condition(item){            return true        }    }    return false}func lessThanTen(number: Int) -> Bool {    return number < 10}var numbers = [20, 18,7,12]println(hasAnyMatches(numbers,lessThanTen))// func and closures ,Use in to separate the argumnet and return type from the bodylet mapValue = numbers.map({(number:Int) -> Int in    let result = 3 * number    return result})let tuple = [1,4,3,45,2]sort(tuple) { $1 > $0}println(tuple)println("---------------------------------")//Object and Classes define and declare =================================//Object and Classes class Shape{    var numberOfSides = 0;    func simpleDescription() -> String {        return "A shape with \(numberOfSides) sides."    }}var shape = Shape()shape.numberOfSides = 7var shapeDescription = shape.simpleDescription()println(shapeDescription)println("---------------------------------")//object and class , important:an initializer to set up the class when an instance  create//“Use deinit to create a deinitializer if you need to perform some cleanup before the object is deallocated.class NamedShape {    var numberOfSide : Int = 0    var name: String        //importmemt:    init(name:String) {        self.name = name    }        //deinit(){}    func shapeDescription() -> String {        return "A simple whith \(numberOfSide) sides"    }}    //class initializervar namedShape = NamedShape(name:"triganle")namedShape.numberOfSide = 3println(namedShape.shapeDescription())println("---------------------------------")//Object and class override//class Square : NamedShape {    var sideLength : Double        init(sideLength: Double, name:String) {        self.sideLength = sideLength        //super 代表父类初始化，也可以重新设置父类的变量值        super.init(name:name)        numberOfSide = 4    }        func area() -> Double {        return sideLength * sideLength    }    //override shapeDescription method    override func shapeDescription() -> String{        return "A spuare whith sides of length \(sideLength)"    }}let test = Square(sideLength : 5.2, name :"my test square")println(test.shapeDescription())println(test.area())println("---------------------------------")//object and class , get and set class EquilaterTriangle : NamedShape {    var sideLength:Double = 0.0        init(sideLength: Double, name : String) {        self.sideLength = sideLength        super.init(name:name)        numberOfSide = 3    }        var perimter: Double {    get {        return 3.0 * sideLength    }    //use set newValue and return new Value    set {        sideLength = newValue / 3.0    }    }        override func shapeDescription() -> String{        return "An equilater triagle with sides of length \(sideLength)"    }}var triangle = EquilaterTriangle(sideLength:10.5,name:"a triangle")println(triangle.perimter)println(triangle.perimter = 11)println(triangle.shapeDescription())