Swift 变量、常量、数据类型

 import Foundation

 print("HelloSwift")

 // 声明变量
 var a =
 var b =
 a =
 b = 

 // 常量
 let c = a+b

 var str = "Hello "
 var s:String = "World"
 var i:Int =
 var words:String = "jinpangpang"

 print(c)
 print(str)