swift（一）基礎變數類型

標籤：

import Foundationprintln("Hello, World!")/*    int a;*/var a = 10 //隱式類型轉換a = 9println(a)let b = 10println(b)/*類型標註*///var x:Int//x = 10.3不支援隱式轉換let x: Int = 10/*名稱不用在符合標示符的規範*/let 常量 = 10/*基礎資料型別 (Elementary Data Type)：整數類型，小樹類書Int8/16/32/64UInt8/16/32/64*/let interger : Int = 10let unsignedInt:UInt32 = 19//let overValue:UInt8 = UInt8.max/*兩種基本類型可不可以進行隱式轉換*/var intVar:Int = 10/*類型推斷和型別安全*/let stringValue = "hello"var uint8value : UInt8 = 9var uint16Value : UInt16 = 9var uint32Value :UInt32 = UInt32(uint8value)+UInt32(uint16Value)//類型轉換/*類型轉換,(類型)運算式*///let floatValue:Double = 1231323var floatValue:Double = 1231323intVar = Int(floatValue)println(intVar)floatValue = Double(intVar)/*布爾類型*/let turnOffLight = 1if turnOffLight==1{    println("Turn OFF")}else{    println("Turn ON")}/*元組：（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)/*可選值:optionals,兩種狀態:有值，沒有值*/var optValue: Int? = nilif (optValue != nil){    println(optValue)}//表示對可選值的一個強制解析，可選值！//var svalue:Int = optValue!//可選綁定if var svalue = optValue{    println(svalue)}/*隱式解析可選類型，兩種狀態，有值，沒有紙nil*/var imOptValue:Int! = 8if (imOptValue != nil){    println(imOptValue)}if let ivalue = imOptValue{    println(ivalue)}var ivalue:Int = imOptValue

 

swift（一）基礎變數類型