swift（一）基础变量类型

import Foundationprintln("Hello, World!")/*int a;
*/
var a = 10 //隐式类型转换
a = 9
println(a)let b = 10
println(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
Int8/16/32/64
UInt8/16/32/64
*/
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 = 9
var uint16Value : UInt16 = 9
var uint32Value :UInt32 = UInt32(uint8value)+UInt32(uint16Value)//类型转换/*
类型转换,(类型)表达式
*/
//let floatValue:Double = 1231323
var floatValue:Double = 1231323
intVar = Int(floatValue)
println(intVar)floatValue = Double(intVar)/*
布尔类型
*/
let turnOffLight = 1
if 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,_) = student
println(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? = nil
if (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! = 8
if (imOptValue != nil){println(imOptValue)
}
if let ivalue = imOptValue
{println(ivalue)
}var ivalue:Int = imOptValue