接口实现中静态变量的含义是什么? [英] What's the meaning of static variables in an implementation of an interface?

问题描述

我不太了解在接口的实现中定义的静态变量.在方法中，我确实理解它们与局部变量有何不同，但在实现中直接定义时则不然.

I don't quite understand static variables when defined in the implementation of an interface. In methods I do understand how they differ from local variables, but not when defined directly in an implementation.

看看这些例子.这两者实际上有什么区别?

Look at these examples. What difference do these two make practically?

#include "MyClass.h"

@implementation MyClass
int myInt;
...
@end

还有:

#include "MyClass.h"

@implementation MyClass
static int myInt;
...
@end

myInt 在这两种情况下对所有方法都是可见的，如果我解释了一个我正确运行的测试，myInt 在这两种情况下对于不同的实例都是相同的变量班级.

myInt is in both cases visible to all the methods, and if I interpreted a test I ran correctly, myInt will in both cases be the same variable for different instances of the class.

推荐答案

该上下文中的 'static' 关键字与普通 C 中的关键字相同:它将 myInt 的范围限制为当前文件.

The 'static' keyword in that context is the same as it would be in plain C: it limits the scope of myInt to the current file.

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