是什么->意思是? [英] What does -> mean?

问题描述

我是Objective-C的相对新手(仅研究过Arron Hillegras的书)，并且对我在Apple的一个代码示例中发现的以下代码片段感到困惑，特别是->是什么意思?

I'm a relative newbie to Objective-C (only studied Arron Hillegras's book) and am confused by the following snippit of code I've found in one of Apple's code examples, in particular what does the -> mean?

-(id) initWithNumbers:(NSArray *)numbers
{
    self = [super init];
    if (self != nil)
    { 
       self->_numbers = [numbers copy];
    }
    return self;
}

在头文件_numbers中声明为

In the header file _numbers is declared as

NSNumber * _number;

(下划线对于我记得在某处所读的内容具有一定的意义，但此刻也使我难以理解.

( the underscore has some significance from what I recall reading somewhere but that too eludes me at the moment.

谢谢 罗宾

推荐答案

->是普通的C运算符，用于将 pointer 的成员访问到结构； .运算符用于访问结构的成员.因此:

-> is a normal C operator for accessing the members of a pointer to a struct; the . operator is for accessing members of a struct. Thus:

a->b

被翻译为

(*a).b

由于Objective-C对象是指向其全部结构的指针，因此可用于访问实例变量.

Since Objective-C objects are pointers to structs underneath it all, this works for accessing instance variables.

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