codecademy swift

As the name implies, when we look up a dictionary, we look at the resources we need to find based on the index, and in Swift, every object in the dictionary contains a key and a value, and we use key to find the value corresponding to the current key. Unlike arrays, data items in a dictionary do not have a specific storage order in the dictionary.Similar to the array in swift, the

Original: Swift language Combat Promotion-1 construction of swift development environmentFor Swift to learn, there must be a development environment. Simply put your Xcode mac system in the right way. So let's take a quick look at what's going on here.1.1 Download XcodeXcode is Apple's programming tool, similar to the Microsoft-produced Visual Studio, which write

In general, the first program in a programming language tutorial should print "Hello, World" on the screen. In Swift, one line of code can be implemented:println ("Hello, World")If you write a C or objective-c code, you should be familiar with this form-in Swift, this line of code is a complete program. You do not need to import a separate library for input or output or string processing. The code in the gl

enumerations Define a set of related values for a common type, so that you can use them in a safe way in your code.If you are familiar with the C language, you will know that in C the enumeration specifies the correlation name as a set of integer values. The enumerations in Swift are more flexible and do not have to provide a value for each enumeration member (enumeration member).If a value (considered "raw" value) is provided to each enumeration memb

subscript may be too small or too large. -You need to input a value to the function, but the invalid value may cause the function to fail to run normally. -An optional value is now nil, but a non-nil value is required for subsequent code execution. Okay, the above is all about Swift's first chapter. The basic part is the basics. The links to all translated articles in Chapter 1 are as follows: Swift learning-

Swift type check and conversion, Swift type check ConversionInheritance occurs in subclass and parent class. It is a series of class inheritance relationship class diagrams. Person is the root class in the class hierarchy, and Student is the direct subclass of Person, worker is the direct subclass of Person.The specific implementation code of this inherited link class diagram is as follows: Class Person {va

This is just a demonstration of how to compile a Web backend project that runs Swift development under Ubuntu.The project code comes from the sample code provided on Bluemix, if you have an account, you can go to your own space to download, no, you can download it through the following address:http://download.csdn.net/detail/testcs_dn/9513395To install the installation configuration of the environment, please refer to: Ubuntu Server installation

Strings and characters (strings and characters)A string is a sequence of characters, such as "Hello, World," or "Albatross." In swift, strings are declared using a string type, which represents a sequence of values consisting of a set of character (character) types.The string type and the character type provide a quick way to process (Unicode-compatible) text in code. The syntax for string creation and management is similar to the C language, both lig

Swift constants and variables and naming rules, swift constant variablesIn the previous chapter, we introduced how to use Swift to write a HelloWorld applet, where variables are used. Constants and variables are important components of expressions.ConstantWhen declaring and initializing a variable, you can add the keyword let before the identifier to specify this

Swift calls C, C ++, Object-C, swift calls cobject-c 1. Swift calls C LanguageA. First, add the CFile file named CHello in the project and generate a bridge file. 　　 B. The project structure after creation is shown in: B. Compile the interface method in CHello. h file, compile the implementation method in CHello. c, and introduce CHello. h In the SwiftCallC-Br

Transferred from: http://www.itjhwd.com/swift-uikitzlx/The term " gravity " seems to be very big in any industry field. So what is gravity in Swift? That is to put the lifeless things on our mobile screen into the gravitational force, so that they can show as if it really fell down due to gravity and the effect of natural bounce after touching an object.To do this, we need two sharp knives: UIKit Dynamics a

After you import a third-party swift package by using Cocopod, the following error is compiled:The "Swift Language Version" (swift_version) build setting must is set to a supported value for targets which use Swift. This setting can is set in the Build Settings editor.The workaround is as follows: (The last time I didn't notice the picture didn't come up, I said,

In order to simplify the swift language, the pointer is cloaked. There is no "*" like that in OC. Give the underlying question to the C language, and we can call the C language in Swift to solve it. Of course, OC can also be called.However, in some scenarios, this invocation may not be very convenient. For example, based on the parsing of the byte stream, the data we receive is parsed, and pointers may be u

Swift is the best language that is second only to PHP. without this second language, Swift makes up for the shortcomings of PHP. [Ridicule Apple] the Swift language is the best language that is only second only to PHP. without such a second language, it makes up for the shortcomings of PHP. Of course, Swift can also do

Swift 2.0 Study Notes (Day 3 )--Swift 2.0 after the added keywordRead the previous study notes.What are the keywords that are now prompting you inSwift 2.0then addDefer,Guard,Repeat,Catch,Rethrows,Throw,Throwsand theTrykeyword, whereRepeatkeyword substitutionDo-whilein the LoopDo, that is, theRepeat-whileloops. andDokeyword is used for error handling. Catch,Rethrows,Throw,Throwsand theTryis the error-hand

Swift calls C, C + +, Object1.Swift calling C languageA, first add the CFile file in the project named Chello, and generate the bridge file.b, after the creation of the project structureb, write the interface method in the CHello.h file, write the implementation method in CHELLO.C, and finally introduce the CHello.h in the Swiftcallc-bridging-header.h file.CHello.h file#ifndef __swiftcallc__chello__#define

Swift explanation 14: swift explanationNSThread asynchronous download of images There are three solutions for processing multithreading in IOS: NSThread, NSOperation, and GCD. Of course, GCD should be the most convenient. We should learn it one by one. First understand the underlying layer, and finally use the most convenient. NSThread:Advantage: NSThread is lighter than the other twoDisadvantage: You need

Swift 2.0 Study Notes (Day 9) -- leave the expression and try again !, Swift Study Notes Swift 2.0 Study Notes (Day 9) -- leave the expression and try again! For Original Articles, please reprint them. Reprinted Please note: Guan Dongsheng's blog Expressions are very important. In Swift, there are three forms of

Analysis process of the Swift programming language and the swift programming language process The Destructor is called immediately before a class instance is released. Deinit is used to indicate the destructor, similar to the initialization function. The Destructor only applies to the class type. Analysis Process Principle Swift Automatically releases instances

Swift difficulties-detailed explanation of the constructor rule instances in inheritance, swift difficultiesConstructing Rules in inheritance is a challenge. If you have any questions, please leave a message to ask me.My Swift getting started tutorial ColumnWhy is there a constructor: assign an initial value to the class itself and the inherited storage attribute