值類型和引用類型
import uikit
func trytochangevalue( var x:int ){x++}
var a:int = 2
tyrchangevalue(a)
a
var b:int = a
b
b++
value type and reference type
int,float,double,bool
tuple
-> value type
string,array,dictionary
function, closure -> reference type
func calctotalmiles( todaymiles:int ) -> ( ) -> int{
var totalmiles = 0
return {totalmiles += todaymiles; return totalmiles;}
}
var dailytwomiles = calctotalmiles(2)
dailytwomiles()
var dailythreemiles = calctotalmiles(3)
dailythreemiles( )
var myplan = dailytwomiles
maplan()
dailytwomiles( )
