iOS #define 或全局字符串的静态常量
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iOS #define or static const for global strings
提问by user1802143
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.
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 static NSString const？#define 有效，但我听说它不是最佳实践。
回答by Bruno Koga
The #defineis a pre-processor macro. That means that it basically goes through your code and replace your macro with what you've defined.
的#define是预处理器宏。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。
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.
如果使用 const，它将是指向内存中字符串的指针。它比在任何地方/任何时候使用相同的字符串都分配更有效。
To do that, you'll need both .h and .m files. Your .h file will look something like:
为此，您需要 .h 和 .m 文件。您的 .h 文件将类似于：
extern NSString * const YOUR_STRING;
And your .m file:
还有你的 .m 文件：
NSString * const YOUR_STRING = @"your string";
