带有 `(反引号)的 Swift 变量名

本文介绍了带有 `(反引号)的 Swift 变量名的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我在浏览 Alamofire 源代码时发现在 这个源文件

I was browsing Alamofire sources and found a variable name that is backtick escaped in this source file

open static let `default`: SessionManager = { let configuration = URLSessionConfiguration.default configuration.httpAdditionalHeaders = SessionManager.defaultHTTPHeaders return SessionManager(configuration: configuration) }()

但是在使用变量的地方没有反引号.反引号的目的是什么?

However in places where variable is used there are no backticks. What's the purpose of backticks?

删除反引号导致错误:

关键字default"不能在这里用作标识符

Keyword 'default' cannot be used as an identifier here

推荐答案

根据 Swift 文档:

要使用保留字作为标识符，请在其前后加上反引号 (`).例如，class 不是有效的标识符，但 `class` 是有效的.反引号不被视为标识符的一部分；`x` 和 x 意义相同.

To use a reserved word as an identifier, put a backtick (`)before and after it. For example, class is not a valid identifier, but `class` is valid. The backticks are not considered part of the identifier; `x` and x have the same meaning.

在您的示例中，default 是 Swift 保留关键字，这就是需要反引号的原因.

In your example, default is a Swift reserved keyword, that's why backticks are needed.