Swfit初学6--协议--结构体--枚举--继承

/*---------------我是帅气的分割线--------*//***  协议*/@objc protocol Description {        func description() -> String    //    mutating func amutatingMethod()    //这里可以改变属性的值    class func aTypeMethod()//类方法需要用class关键字    @optional func anOptionalMethod()}//如果声明可选择实现方法. 需要在func前加@optional声明,而且协议前面要加@objc 这样协议结构体不能遵守,所以也不允许matating方法的存在//protocol Description{//    func description() -> String//    mutating func aMutatingMethod()//    class func aTypeMethod()    //类型方法需要用class关键字//    @optional func anOptionalMethod()//    //}/*---------------我是帅气的分割线--------*//*------- 结构体 -------*/struct Point {    var x = 0.0    var y = 0.0}struct Size {    var width = 0.0    var height = 0.0}// Swift中结构体也可以创建("对象")实例var point = Point()var size = Size()//创建两个空的数组var anEmptyArrayA = Array<String>()// orvar anEmptyArrayB = String[]()struct Rect{    ///------------>遵守协议,下面实现方法    var origin = Point()    var size = Size()    //计算属性必须是变量    var center: Point{    get{        let centerX = origin.x + size.width / 2        let centerY = origin.y + size.height / 2        return Point(x: centerX , y:centerY)    }    set (getCenter){               //--------> setter方法会提供一个默认的新值,newValue        let originX = getCenter.x - size.width / 2        let originY = getCenter.y - size.height / 2        origin = Point(x: originX,y: originY)    }    }            mutating func  moveBy(deltaX:Double,deltaY: Double){        let newX = origin.x + deltaX        let newY = origin.y + deltaY        origin = Point(x:newX , y:newY)        }            //------实现协议方法    func description() -> String{        return "(\(origin.x),\(origin.y),\(size.width),\(size.height))"    }        mutating func aMutatingMethod(){        //这里可以改变属性的值    }        // 如果是现实协议中的类型方法,虽然在协议中使用了class关键字,但是在结构体    static func aTypeMethod() {            }        }var frame = Rect()frame.origin.x = 10frame.origin.y = 10//frame.size.width = 10//frame.size.height = 10frame.size = Size(width: 100, height:100)println("frame = (\(frame.origin.x),\(frame.origin.y),\(frame.size.width),\(frame.size.height))")println("frame.center = (\(frame.center.x),\(frame.center.y))")println(frame.description())/*---------------我是帅气的分割线--------*//***  枚举值*/enum PersonIdeentify: String {    case Teacher = "teacher"    case Student = "student"}class Person{    var name:String?    var sex:String?    var identify:PersonIdeentify?        //构造器中,第一个参数依然会创建一个和局部参数名称相同的外部参数名称    init(name: String,sex: String, identify: PersonIdeentify){        self.name = name        self.sex = sex        self.identify = identify    }            //实现协议方法    func description() -> String{        // 调用枚举值的toRow()方法可以获取到枚举值的初值        return "(name = \(name) sex = \(sex) identify = \(identify!.toRaw()))"    }        // 在类中如果实现协议中定义的mutating方法,那么不需要加"mutating"关键字    func aMutatingMethod(){        }        }//前面声明枚举,直接可以用" .Student "再次说明自动类型推断var personA = Person(name: "张三",sex :"m", identify: .Student)var personB = Person(name: "lisi",sex :"f", identify: .Teacher)switch (personA.identify!){case .Teacher:    println("I am teacher")case .Student:    println("I am Student")}/*---------------我是帅气的分割线--------*//***   继承*/class Student: Person {    var number: String?    // 在类中,类型属性只可以是计算属性,但是在枚举和结构体中,既可以是计算属性,也可以是存值属性    // 在类中声明一个类型属性的关键字class,在结构体和枚举中是static    class var attendClassTime: String {        return "9:30"    }        init(name: String,sex:String,number:String){        super.init(name:name,sex:sex,identify:.Student)             //继承父类        self.number = number                                        //自己的初始化    }    }var studentA = Student(name: "李莉",sex: "f",number:"312321")var studentB = Student(name: "李莉",sex: "f",number:"312321")println("Student attendClassTime = \(Student.attendClassTime)")class Teacher:Person {    var course:String?    init(name: String,sex:String,course:String){        super.init(name:name,sex:sex,identify:.Student)        self.course = course    }        override func description() -> String{      ///----------我重写之前的方法(协议中),加上关键字 override        return super.description() + "" + "course = \(course)"        }    }var teacherA = Teacher(name:"张阳",sex:"男",course:"Swfit")println()