iOS #define或全局字符串的静态const [英] iOS #define or static const for global strings

问题描述

我有一个constants.h文件，它声明了我在整个应用程序中使用的一堆字符串。我只有字符串，没有别的。我应该使用#define还是静态NSString const？ #define有效，但我听说它不是最佳做法。

I have a constants.h file that declares a bunch of strings that I use throughout my app. I only have strings and nothing else. Am I supposed to use #define or static NSString const? #define works but I hear its not best practice.

推荐答案

#define 是一个预处理器宏。这意味着它基本上会遍历您的代码并用您定义的内容替换您的宏。

The #define is a pre-processor macro. That means that it basically goes through your code and replace your macro with what you've defined.

如果您使用const，它将成为指向字符串的指针在记忆中。它比在任何地方/任何地方分配相同的字符串更有效。

If you use a const, it's going to be a pointer to the string in memory. It's way more efficient than having the same string being allocated wherever/whenever it is used.

为此，你需要.h和.m文件。您的.h文件类似于：

To do that, you'll need both .h and .m files. Your .h file will look something like:

extern NSString * const YOUR_STRING;

和你的.m档案：

NSString * const YOUR_STRING = @"your string";

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