(1)变量与常量
(2)基本类型
(3)强制转换
(4)Bool类型
(5)元组
(6)可选值
//变量和常量
var str = "Hello, playground"
let maxNum = 888
//指定类型
var str1:String = "test"
var int1:Int = 1
var dou1:Double = 1.11
var flo1:Float = 1.111111111111
//强制转换
var dou2:Double = Double(int1) + dou1
//Bool类型
var bool1:Bool = true
bool1 = false
if bool1 {
println("i am true")
} else {
println("i am false")
}
//元组
var registionResult = (name:"姓名",age:24,sex:"女")
var connectionResult = ("404","Not Found!")
registionResult.age
registionResult.name
registionResult.sex
var registion:(name:String,age:Int,sex:String)
registion.name = "xxx"
//可选值
var a:Int?
a = 12
a = "12".toInt()
println("age is" + String(a!))