var MyAge = 10

var YourAge = 11

var Total = Float(MyAge)+Float(YourAge)

let apple = 2

let orange = 4

let say1 = "I have \(apple) apples\n"

let say2 = "I have \(apple+orange) pieces of fruit."

println(say1+say2)

//结果：
//I have 2 apples

//I have 6 pieces of fruit.

let π = 3.14159
let 网址 = "http://www.cnblogs.com/walter371"
let {emoji表情} = "王大力和王二力"
//emoji表情是一种特殊的Unicode字符
//在mac上可以使用快捷键：control+command+空格来调出emoji表情