Swift

written Questions Beginner question 1, (problem with Swift 1.0 and later) has a better way to write the following for loop. 1 2 3 for var i = 0; I Answer: 1 2 3 For _ in 0...4 {print ("hello!")}

Func Application (_ Application:uiapplication, didfinishlaunchingwithoptions launchoptions: [ Uiapplicationlaunchoptionskey:any]?) -Bool {If #available (IOS 10.0, *) {Unusernotificationcenter.current (). Requestauthorization (options: [. Sound,.

1.Let Cornervalue = uirectcorner.topright.rawvalue| UIRectCorner.bottomRight.rawValueLet corner = Uirectcorner (Rawvalue:cornervalue)Let path = Uibezierpath.init (RoundedRect:wifiLabel.bounds, Byroundingcorners:corner, CornerRadii:CGSize.init (width:

Both class and structure can do: Define Properties to store values Define methods to provide functionality Be extended Conform to Protocols Define intialisers Define subscripts to provide access to their variables

Extension of the UIViewExtension UIView{ func Getfirstviewcontroller ()-uiviewcontroller?{ For view in sequence (first: Self . Superview, Next: {$?. Superview}) {if let responder = view?. next{ if responder. Iskind (of: Uiviewcontroller. Self) {

After upgrading swift3, the data type of the Devicetoken returned when using the Didregisterforremotenotificationswithdevicetoken method, The printed Devicetoken value is "32byte".Here are two ways to go to print DevicetokenLet device = NSData (Data:

Picture size size刚刚开始接触的话，从美工那边拿来的图标大小一般都是偏大的，就像这样：在此建议，tabBar的图标大小可以是32*32,个人感觉效果不错Color problems with pictures如所示，该图标的期望颜色（也就是美工给的原图）如所示：那么问题来了，为什么会变成灰色的呢？经查阅后得知。这是因为在默认情况下，未选中状态图片和字体颜色为灰色，选中状态片和字体颜色为蓝色。法1：通过xib面板设置 ——

A construction process is a preparation process that precedes an instance of a class, struct, or enumeration type. You must perform this procedure before a new instance is available, including setting the initial value of each stored-type property

Class func Ispassword (pasword: String), Bool { let pwd = "^ (?! [0-9]+$) (?! [a-za-z]+$] [0-9a-za-z]{6,16}$ ]Let regextestpwd = nspredicate (format: "Self MATCHES%@", pwd) if (regextestpwd. Evaluate (With:pasword) = = true) { return true

Use let to declare constants, and use Var to declare variables.The compiler automatically infers the type without having to explicitly declare the type and assign the value at the same time as the declaration. If the initial value does not provide

var numbers = [0,1,2,3,4,5];var vowels = ["A", "E", "I", "O", "U"];var Emptyarr = [Int] ();Number of array elementsPrint ("The length of the array is: \ (numbers.count), \ (Vowels.count), \ (Emptyarr.count)");Empty sentenceIf Numbers.isempty {Print (

1. Create a collection (unordered and non-repeatable)(1) Create an empty collectionvar a=set ()//[](2) Create a collectionvar a:set=[1,2,3]//[2,3,1]2. Insert in the middle of the collectionvar A:set=[1,2,3]a.insert (4)//[2,4,3,1]3, set (remove)

1.swift pay attention to the use of point syntax, beginning will be a bit unaccustomed. Some of the code used by OC is used to change.2. We use #pramgram Mark #warning之类的标记注释 in OC, which is not available in Swift, we want to change//mark:

viewcontroller.swift//learn5////Created by MYHASPL on 16/1/23.//Copyright (c) 2016 MYHASPL. All rights Reserved.//import Cocoaimport Foundationclass viewcontroller:nsviewcontroller {override func ViewDidLoad () {super.viewdidload ()//Do any

1,as Use occasions(1) converting from derived class to base class, upward transformation (upcasts)1 class Animal {} 2 class Cat:animal {} 3 Let cat = cat ()4 as Animal(2) Elimination of ambiguity, numeric type conversion1 the as CGFloat 2 the as

main.swift//classdemo-06//import foundationprintln ("Hello, world!") Class definition person Name class person{//define a field age var age:int = 0; Define a field name//? Indicates that name is null nil or not set name is optional var

To make use of. Let to declare constants, so that var to declare the variable. ? A constant value is not required at compile time, but you can only assign a value to it. So you can? Use constants to table? A value: You just have to decide, but

Note: After the push is set self.hidesbottombarwhenpushed=no;//so back, Tabbar will return to normal display.Let Detailctrl = Scanviewcontroller (nibname: "Scanviewcontroller", Bundle:nil); Detailctrl.hidesbottombarwhenpushed = True

When learning new things, I often encounter some problems that I cannot solve at the time. I want to record them and understand them in depth, but I will always forget them. So, right! This article is a pitfall! Leave it blank! Problem description:

In the previous article, the translation introduced Part 1 of the Basic API information in the official swift documentation. This article completes the API operations of the most important storage service. Now let's get started = d 3. Storage