空方法名称，这实际上做了什么？ [英] Empty method name, what does this actually do?

问题描述

我目前正在学习自己的Objective-c和iOS编程，并且由于这个微妙的错误持续了一个小时，我发现自己陷入了非工作代码。
考虑以下代码：

I'm currently learning myself objective-c and iOS programming and found myself stuck with non-working code due to this subtle error for an hour. Consider the following code:

@property (strong, nonatomic) NSString *name;
- (NSString *):name { return @"Some name"; }

乍一看（对于任何新人）这看起来像是一个被覆盖的<$ c的getter $ c> name property。但是有一个非常微妙的：，不应该存在。这里没有来自编译器/解析器/运行时的警告/错误，所以我的问题是这实际上最终是什么？

At first glance (and for anyone new) this looks like an overridden getter for the name property. But theres a very subtle : that shouldn't be there. You get no warning/error from the compiler/parser/runtime here, so my question is what does this actually end up as?

我试图找到一种调用方式这个方法一旦我看到错误，但在我的几次尝试中都没有成功。

I tried to figure a way of calling this method once I saw the error, but didn't succeed in my few attempts.

推荐答案

方法签名 - （NSString *）：name 分解为以下内容：

The method signature - (NSString *):name breaks down to the following:

• - 这是一个实例方法（与 + 的类方法相比）。


• （NSString *）它返回一个字符串。


• ：如果你要说的话这个方法的名称，简称为冒号。 ：告诉编译器您的方法也接受一个参数。


• name 有一个名为name的参数。

• - It is an instance method (versus a class method with a +).
• (NSString *) It returns a string.
• : If you were to speak the name of this method, it would simply be called "colon". : tells the compiler that your method accepts one parameter as well.
• name There is a parameter called name.

当您未指定类型时，编译器假定您的意思是 id ，所以这个方法实际上是 - （NSString *）:( id）你好

When you don't specify a type, the compiler assumes you meant id, so this method actually fleshes out to be - (NSString *):(id)hello

有效对此方法的调用将是： [self：@hello] 。

A valid call to this method would be: [self :@"hello"].

你可以做一些非常奇怪的事情因为：是方法的有效名称，编译器假定 id 。如果你真的想，你可以使用一个名为 - ::: 的方法。编译器会假设你的意思是 - （id）:( id）:( id）:( id），一个返回类型对象的方法id 并采用类型 id 的三个参数。你会这样称呼： [self：@hello：anObject：myObject];

You can do really weird things because : is a valid name for a method, and the compiler assumes id. You could, if you really wanted to, have a method called - :::. The compiler would assume you meant - (id):(id):(id):(id), a method that returns an object of type id and takes three parameters of type id. You'd call it like so: [self :@"hello" :anObject :myObject];

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