具有 Swift 3 属性的单例 [英] Singleton with properties in Swift 3

问题描述

在 Apple 的 将 Swift 与 Cocoa 和 Objective-C 文档一起使用(针对 Swift 3 进行了更新)他们给出了以下单例模式示例:

In Apple's Using Swift with Cocoa and Objective-C document (updated for Swift 3) they give the following example of the Singleton pattern:

class Singleton {
    static let sharedInstance: Singleton = {
        let instance = Singleton()

        // setup code

        return instance
    }()
}

让我们想象一下，这个单例需要管理一个可变的字符串数组.我将如何/在哪里声明该属性并确保它正确初始化为空的 [String] 数组?

Let's imagine that this singleton needs to manage a variable array of Strings. How/where would I declare that property and ensure it gets initialized properly to an empty [String] array?

推荐答案

对我来说这是最好的方法，将 init 设为私有.Swift 3 4 5 语法

For me this is the best way, make init private. Swift 3 4 5 syntax

// MARK: - Singleton

final class Singleton {

    // Can't init is singleton
    private init() { }

    // MARK: Shared Instance

    static let shared = Singleton()

    // MARK: Local Variable

    var emptyStringArray = [String]()

}

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