SWIFT Tuple Pattern及Struct Pattern

定义一个Tuple

let color = (1.0,1.0,1.0,1.0)

switch color{

case (0.0,0.5...1.0,let blue,_): //匹配第一个值为0.0第二个值为0.5到1.0第三四值为任意，并将第三个值传给blue变量

println("Blue is \(blue)")

case let (r,g,b,1.0) where r == g && g == b: //额外条件where 本个亦是的值要相等

println("Opaque grey \(r * 100)%")

default:

println("unkonw")

}

匹配模式混合应用，更加强大及有效，

class State{

var name:String?

var population:Double?

var abbr:String?

init(name:String,pop:Double,abbr:String){

self.name = name

self.population = pop

self.abbr = abbr

}

}

func stateFormPlist(list:Dictionary<String,AnyObject>) -> State? {

switch(list["name"],list["pupulation"],list["abbr"]){ //创建Tuple，检查要检查的元素

case (

.Some(let listName as NSString), //对应相对应位置的Tuple元素

.Some(let pop as Double),

.Some(let abbr as NSString)

) where abbr.length == 1:

return State(name: listName, pop: pop, abbr: abbr)

default:

println("b")

}

return nil

}

var mylist = ["name":"Beijing","population":20000000,"abbr":"京"]

var result = stateFormPlist(mylist)

println(result?.abbr)  //京

println(result?.name) //Beijing

println(result?.population) //20000000

元祖就说完了，接下来定义一个Struct

struct Color {

var red:Double?

var green:Double?

var blue:Double?

var alpha:Double?

init(red:Double,green:Double,blue:Double,alpha:Double){

self.red = red

self.green = green

self.blue = blue

self.alpha = alpha

}

}

var mycolor = Color(red: 10, green: 20, blue: 60, alpha: 1.0)

switch mycolor{

case let a where a.red == 10 && a.blue == 60:

println("yes")

default:

println("unkonw")

}

使用下划线(_)忽略部分数值：

var loginResult = (true, "Login Success")

let (isLoginSuccess,_) = loginResult

if isLoginSuccess {

println("登录成功")

println(loginResult.0)  //访问Tuple中的第一项

println(loginResult.1)  //访问Tuple中的第二项

}