元组，可以包含不同的数据类型

var point1 = ( 5, 2)
var httpResponse1 = ( 404 , "Not fount")

var point2 : ( Int, Int , Int) = ( 3, 3, 3)
var httpResponse2 : ( Int, String) = ( 200, "OK")
let point3 : ( x: Int, y: String) = ( 5, "Smiley")


//元组的解包
let ( x, y) = point1
let ( statusCode, statusMessage) = httpResponse1

//取元组中的分量
point1.0
httpResponse1.1
point3.x
point3.y


//解包忽略不需要的值时 _ 代替
let loginResult = ( true , "adsjgnai")
let (isLogin , _) = loginResult
if isLogin == true {
    print("isLogin")
}else{
    print("login failed")
}