C# 中 object 与 Objective C 的等价物是什么？
在 c# 中，我可以声明 object o; 然后我可以分配 o=(float)5.0; 或 o="a string." 有吗Objective-C 的等价物？我尝试使用 id ，但它不采用浮点或整数等基本类型。谢谢你的帮助。
In c# I can declare object o; then I can assign o=(float)5.0; or o="a string." Is there an equivalent for Objective-C? I tried to use id but it does not take primitive type like float or integer. Thanks for helping.
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Objective-C 并没有 CLR 所说的“统一类型系统”。换句话说，作为 C 的超集，Objective-C 的原始类型与对象实例完全不同。
id类型可以存储对任何对象实例的引用（实际上是 OS X/iPhone Objective-C 运行时中的指针）。 C 的原始类型（例如int、float等）必须包裹在NSValue或NSNumber中才能赋值输入id。当然，这正是 C# 编译器正在做的事情。只是在 C# 中，您不必显式执行装箱（拆箱）转换。很快，类似的代码
将成为第二天性，但不幸的是，按照现代标准来看，这些代码很冗长。
Objective-C doesn't have a "unified type system" in the words of the CLR. In other words, as a superset of C, Objective-C's primitive types are different beasts altogether than object instances. The
idtype can store references (really pointers in the OS X/iPhone Objective-C runtime) to any object instance. C's primitive types (e.g.int,float,etc.) must be wrapped inNSValueorNSNumberto be assigned to typeid. Of course, this is exactly what the C# compiler is doing. It's just that in C#, you don't have to do the (un)boxing conversion explicitly.Pretty soon, code like
will become second nature, if unfortunately verbose by modern standards.
确实没有这样的事情。您可以使用
NSNumber或NSValue将本机数据类型作为对象处理。NSString将处理字符串。您可以将所有这些分配给id类型变量，但您需要使用正确的类的init方法来创建它们。There isn't really such a thing. You can use
NSNumberorNSValueto handle native data types as objects.NSStringwill do strings. You can assign all of those to anidtyped variable, but you'll need to create them with the correct class'sinitmethods.你是对的，
id仅适用于 ObjC 对象引用。如果您想通过 id 引用来引用 int，则需要将其装箱到NSNumber中。顺便说一句，C# 也对这些原语进行装箱，它只是自动执行。You are correct,
idonly works for ObjC object references. If you want to reference an int with an id reference, you need to box it into anNSNumber. Incidentally, C# is boxing those primitives too, it's just doing it automatically.在我那个时代，我们必须在雪地里步行 15 英里，上坡，才能使用 空指针。哦，我们没有 StackOverflow！
Back in my day we had to walk 15 miles in the snow, uphill, to use void pointers. Oh, and we didn't have StackOverflow!
实际上，C# 数据类型只是其各自类的别名，这就是它们可以分配给对象类型的原因。
例如，int实际上是一个名为Int32的类。
正如@Barry 之前提到的，Objective-C 的情况并非如此。
Actually, C# data types are just aliases for their respective classes and that's why they can be assigned to object type.
For example, int is actually a class called Int32.
As @Barry mentioned earlier, that's not the case with Objective-C.