字符串前@符号的用途？ [英] Purpose of @ Symbol Before Strings?

问题描述

我一直在使用Objective-C一段时间，但从来没有真正理解所有字符串之前@符号的用途是什么。例如，为什么你必须声明这样的字符串：

I've been using Objective-C for a while now, but have never really understood what the purpose of the @ symbol before all strings is. For instance, why do you have to declare a string like this:

NSString *string = @"This is a string";

而不是这样：

NSString *anotherString = "This is another string";

就像在Java或许多其他编程语言中一样。有充分的理由吗？

as you do in Java or so many other programming languages. Is there a good reason?

推荐答案

它表示NSString（而非标准C字符串）

It denotes a NSString (rather than a standard C string)

NSString是一个存储unicode字符串的Object，它提供了一堆方法来帮助操作。

an NSString is an Object that stores a unicode string and provides a bunch of method to assist with manipulating.

一个C字符串只是一个\0终止一堆字符（字节）。

a C string is just a \0 terminated bunch of characters (bytes).

编辑：好的原因是Objective-C构建在C之上，C语言结构需要是仍然可用。 @是仅限目标c的扩展名。

and the good reason is that Objective-C builds on top of C, the C language constructs need to be still available. @"" is an objective-c only extension.

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