Swift 笔记1

// Playground - noun: a place where people can play

import Cocoa

var str = "Hello, playground"

// 定义常量

let schoolNum:String="罗子山中心小学"

// 定义变量

var age:Int=19

age=28

// 显示转换

var ageFolat:Float=Float(age)

// 数组、字典

var shoppingList=["catfish","water","blue paint"]

shoppingList[1]

var occupations=["1":"water","2":"apple"]

occupations["1"]

occupations["3"]="admin"

occupations["3"]

// 创建空的数组和字典

let emptyArray = [String ]()

let emptyDictionary=Dictionary<String,Float>()

// 循环

let indicdualScores=[75,43,103,89]

var teamScore=0

for score in indicdualScores{

if score>50{

println(score)

}else{

println(score+1)

}

}

// 可空

var optionalString:String?="Hello"

optionalString=nil

var strGreeting:String?="hello"

if let name=strGreeting{

println(name)

}

var ass:String=" 222321"

//switch

let vegetable="Red popper"

switch vegetable{

case "celery":

let vegetableComment="Add Somen"

case "Red","Bule":

let vegetableComment="Update Somen"

case let x where x.hasSuffix("popper") :

let vegetableComment="Delete from"

default :

let vegetableComment="Default"

}

// for in遍历 字典

/*

let interestingNumbers=["1":[1,2,3,4,5],"2":[9,8,7,6,5]]

var largest=0

for(kind,numbers) in interestingNumbers{

for number in numbers{

if number > largest

largest=number

}

}

*/

// while

var n=2

while n<100{

n=n*2

}

println(n)

// ..表示区间

/*

var firstForLoop = 0

for i in 0..3{

firstForLoop += i

}

println(firstForLoop)

*/

for var i=0;i<3; ++i{

println(i)

}

// 方法

func greet(name:String,day:String)->String{

return "hello\(name),Today is\(day)"

}

greet("tony", "1")

func getGasPrices()->(Double,Double,String){

return (3.123,123.2,"tony")

}

getGasPrices()

// 方法参数可以是动态的

func sunOf(numbers:Int...)->Int{

var sum=0

for number in numbers{

sum+=number

}

return sum

}

sunOf()

sunOf(12,32,32)

// 函数可以嵌套

func returnFifteen()->Int{

var y=10

func add(){

y+=5

}

add()

return y

}

returnFifteen()

var aa=123

// 函数可以作为另外一个函数返回值

/*

func makeIncrementer()->(Int->Int){

func addOne(number:Int)->Int{

return 1+number

}

return addOne

}

var increment=makeIncrementer()

increment(8)

*/