邻家swift初长成

import Foundation

let  str = "123"

var  message = "tuqiushuang , str"

message+="t"//字符追加

if str.isEmpty||200>90

{

    print("hao")

}

if str==message&&100>90

{

    print("hao")

}

else

{

    print("hao==")

}

var  a = 1

var  b = 2

let m = "(str) and (Double(a)*0.1)"//字符串的插入

var d = a>b ? "优秀" : "良"

var arr: [String] = ["eggs","milk","dd"]//数组

for item in arr{//遍历

    print(item)

}

for(index, value)in EnumerateSequence(arr)

{

    print("item (index+1):(value)")//遍历

    //元组类型下标与值

}

arr.append("jidan")

arr+=["wo","he"]

print(arr.count)

arr.insert("insert", atIndex: 2)//在某个位置插入

let aa = arr.removeAtIndex(5)//删除的那个值

let apple : Int? = 123//可选类型

var httpStatus=(s:200,d:"ok",m:90)//tuple元组类型,类似字典

    httpStatus.m

/*

 字典<尖括号里是:指定类型>

 */

var  airporits:Dictionary <String,String>= ["K0":"V0","K1":"V1"]

airporits["k2"]="v2"//追加

airporits.count//对的个数

if let removevalue=airporits.removeValueForKey("K1")

{

    print(removevalue)

    

}else{

    print("NO have")

}

for i in 0 ..< 10 {

    if i%2==0{

        continue;//跳转语句

    }

    print("i = (i)")

}

//函数嵌套

func chooseStepFunction(backwards:Bool) ->(Int)->Int{

    

    func stepForward(input:Int)->Int{

        return input+1

    }

    func stepBackward(input:Int)->Int{

        return input-1

    }

    return backwards ? stepBackward : stepForward

}

var currentValue = -4

let moveNearerToZero = chooseStepFunction(currentValue>0)

while currentValue != 0 {

    currentValue = moveNearerToZero(currentValue)

    print(currentValue)

}

//闭包

struct imageFile{//结构体 图片文件

    var fileName = String()

    var fileID = Int()

}

var  images:[imageFile] = []

var new = imageFile(fileName: "hehe",fileID: 20)

var old = imageFile(fileName: "heihei",fileID: 30)

images.sort({ $0.fileID>$1.fileID})

images.sort({image1,image2 in image1.fileID > image2.fileID})

old.fileID

new.fileID

//计算属性

struct Point{

    var x = 0.0, y = 0.0

}

struct Size {

    var width = 0.0, height = 0.0

}

struct Rect {

    var origin = Point()

    var size = Size()

    

    var center: Point {

    get {

        let centerX = origin.x + (size.width / 2)

        let centerY = origin.y + (size.height / 2)

        return Point(x:centerX, y:centerY )

        }

    set(newCenter){

            origin.x = newCenter.x - (size.width / 2)

            origin.y = newCenter.y - (size.height / 2)

        }

}

}

var square = Rect(origin: Point(x: 0.0, y: 0.0), size: Size( 10.0, height: 10.0))

let initialSquareCenter = square.center

square.center = Point(x: 15.0, y: 15.0)

print("矩形边长:(square.origin.x),(square.origin.y)")

原文地址:https://www.cnblogs.com/linximu/p/5830691.html