Home > Web Front-end > JS Tutorial > body text

Method instances for defining singletons in Swift

php中世界最好的语言
Release: 2018-04-11 14:09:45
Original
1583 people have browsed it

This time I will show you how to define a singleton in Swift and what are the precautions for defining a singleton in Swift. The following is a practical case, let's take a look.

What is a singleton

Single case pattern is the simplest one among design patterns. Even some pattern masters do not call it a pattern, but call it an implementation technique, because the design pattern pays attention to the object. The abstraction of the relationship between objects, while the singleton mode has only one object of its own.

Singleton Pattern, also called monad pattern, is a commonly used software design pattern. When applying this pattern, the class of a singleton object must ensure that only one instance exists.

The Singleton design pattern may be the most widely discussed and used design pattern, and it may also be the most frequently asked design pattern in interviews. The main purpose of this design pattern is to ensure that only one instance of a class can appear in the entire system. Of course, this is necessary, such as the global configuration information of your software, or a Factory, or a main control class, etc.

How to create a singleton in swift

There are the following two ways to create a singleton in swift

The way of global variables

let sharedNetworkManager = NetworkManager(baseURL: API.baseURL)
class NetworkManager {
 // MARK: - Properties
 let baseURL: URL
 // Initialization
 init(baseURL: URL) {
 self.baseURL = baseURL
 }
}
Copy after login
Use this global variable for

reference

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
 print(sharedNetworkManager)
 return true
}
Copy after login

StaticAttributes and privatizationConstruction method

class NetworkManager {
 // MARK: - Properties
 private static var sharedNetworkManager: NetworkManager = {
 let networkManager = NetworkManager(baseURL: API.baseURL)
 // Configuration
 // ...
 return networkManager
 }()
 // MARK: -
 let baseURL: URL
 // Initialization
 private init(baseURL: URL) {
 self.baseURL = baseURL
 }
 // MARK: - Accessors
 class func shared() -> NetworkManager {
 return sharedNetworkManager
 }
}
Copy after login
Directly call the class method for reference

NetworkManager.shared()
Copy after login
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

Recommended reading:

How to use the on-change attribute in IView

How to use sass configuration in the vue project

The above is the detailed content of Method instances for defining singletons in Swift. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template