import Foundationprintln("Hello, World!")/*    int a;*/var a = 10 //隐式类型转换a = 9println(a)let b = 10println(b)/*类型标注*///var x:Int//x = 10.3不支持隐式转换let x: Int = 10/*名称不用在符合标示符的规范*/let 常量 = 10/*基本数据类型：整数类型，小树类书Int8/16/32/64UInt8/16/32/64*/let interger : Int = 10let unsignedInt:UInt32 = 19//let overValue:UInt8 = UInt8.max/*两种基本类型可不可以进行隐式转换*/var intVar:Int = 10/*类型推断和类型安全*/let stringValue = "hello"var uint8value : UInt8 = 9var uint16Value : UInt16 = 9var uint32Value :UInt32 = UInt32(uint8value)+UInt32(uint16Value)//类型转换/*类型转换,(类型)表达式*///let floatValue:Double = 1231323var floatValue:Double = 1231323intVar = Int(floatValue)println(intVar)floatValue = Double(intVar)/*布尔类型*/let turnOffLight = 1if turnOffLight==1{    println("Turn OFF")}else{    println("Turn ON")}/*元组：（30，“hello”）*/let student:(String,Int,Double) = ("zhangsan",23,98.5)println(student.0)println(student.1)println(student.2)let(name,age,_) = studentprintln(name)println(age)//println(score)let student1 = (name:"zhangsan",age:23)println(student1.name)println(student1.age)/*可选值:optionals,两种状态:有值，没有值*/var optValue: Int? = nilif (optValue != nil){    println(optValue)}//表示对可选值的一个强制解析，可选值！//var svalue:Int = optValue!//可选绑定if var svalue = optValue{    println(svalue)}/*隐式解析可选类型，两种状态，有值，没有纸nil*/var imOptValue:Int! = 8if (imOptValue != nil){    println(imOptValue)}if let ivalue = imOptValue{    println(ivalue)}var ivalue:Int = imOptValue