Swift

This article is written under the playground of XcodeSo what is playground?When it comes to playground we have to mention swift, the language that Apple has pushed recently, and Swift is the new development language that Apple has released on WWDC201

before specific actions are added ! symbols, okay, what is this weird grammar?! Let digit = sender. Currenttitle !Here's ! said, "I'm sure the strvalue here must be non-nil, call it", for exampleIf Userisinthemiddleoftypinganumber { //== true

var str_componets = "I like Swift"Str_componets.componentsseparatedbystring ("")In this way, the str_componets is divided into four sections:["I", "like", "Swift", "" ")You can also use Nscharacterset to split:var str_componets = "I would prefer a

Swift's string class does not contains a method of this type to directly determine whether a string contains another string, but it can be implemented flexibly.Directly on the code:If "This is a string". Componentsseparatedbystring ("string"). Count

Suppose a zlanimal class. I need to create TA when keeping a singletonThe practice in OC Static dispatch_once_t Oncetoken; Dispatch_once (&oncetoken, ^{ _instance = [[Zlanimal alloc] init]; });The approach in Swift is similar in that

Here are the parsing, generation methodsfunc jsonparse () { /****************************************** parsing json type ************************************** / let jsonfile = nsbundle. Mainbundle(). Pathforresource("Jsonparsefile", OfType:

Cyclic strong references in closuresResolving cyclic strong references between closures and class instances can be achieved by defining a capture list.Capture ListEach element in the capture list is made up of a reference to the weak or unowned

Property delay Store Property objective-c practicesSometimes we need to defer loading properties, which can be implemented in objective-c by overriding the getter method:@property(nonatomic,Strong)Nsmutablearray*players;-(Nsmutablearray*) Players

//Playground-noun:a Place where people can playImport UIKit//a few important concepts Properties/methods/subscripts/initialization/extensions/protocols/inheritance/type Casting/ Deinitialization/automatic Reference Counting//definition

//Playground-noun:a Place where people can playImport UIKit//Enumeration Syntaxenumsomeenumeration {//enumeration definition goes here}//defines an enumerationenumCompassPoint { Case North Case South CaseEast CaseWest}//When you declare an

ARCFull name automatic reference counting, is a memory management mechanism. When the number of strong references to a block of memory equals 0, the memory is freed.Because enumerations and structs are value types in swift, they are not stored and

var nsurl:nsurl = Nsurl (string:api_host+ "/" +LOGIN_API)!var request = Nsmutableurlrequest (Url:nsurl)Request. HttpMethod = "POST"var postkeyjson:nsstring = "\ (loginpostkey)" + "=" + "{\" email\ ": \" \ (username) \ "\" password\ ": \" \ (Userpass)

1.for in loopFor by multiplier in 1...5{println ("\ (by multiplier) multiplied by 5 is \ (by multiplier)")}When you do not need the first variable, you can use _ instead, for example, to ask for 3 of the 10-squareLet Bottom =3Let Power =10var result

Base and Derived Classes:classbaseclass{classfunc Staticmethod () {println ("Baseclass.staticmethod") } classfunc Staticmethodwithselfcall () {Self.staticmethod ()} func Instancemethodwithstaticcall () {s Elf.dynamicType.staticMethod

The Swift language released by Apple can exist in one project with the previous objective-c language.There may be people who think that there can be objective-c or swift in the same class file, which is not right. In the same class file or in the

String and character nonalphanumeric compatible Unicode in SwiftDefine a stringLet's hello= "Hello World"Initialize an empty stringLet hello= ""Let Hello=string ()Determines whether a string is emptyIf hello.isempty{println ("This is an empty string"

Swift's regular expression, you can customize a class for easy invocationClass Regex {Let Internalexpression:nsregularexpressionLet pattern:stringInit (_ pattern:string) {Self.pattern = Patternvar error:nserror?Self.internalexpression =

Today I tried the swift CoreData encountered a strange problem:When you run the project, you will be prompted to not find the class file that corresponds to the entity, but in the entity, the file is actually created and actually existsRun to this

UITableView is the most commonly used control in app development and is powerful enough for the display of data. The basic usage is described in a simple example below.build a project firstThe code is as follows:Import Uikitclass

Variables are declared with Var, constants are all let, variable names are not limited to the noon expression can be, generally still use Englishvar str = "Luoshuai" is not required after the//swift statement;Let PI = 3.14159var age = 0, height