c++ - C++ 结构中私有和受保护的可用性

Question

我们可以在 C++ 结构（而不​​是类）中使用访问说明符 -private和- 吗？protected

另外，C 中是否存在访问修饰符？

Answer 1

C doesn't have C++style access modifiers. A C struct is just a composite object type containing members of other object types.

In C++, a struct and a class are almost identical; the only difference is that struct members are public by default, and class members are private by default. So this:

struct foo {
private:
    // ...
};

is equivalent to this:

class foo: {
    // ...
};

This has been answered elsewhere.

This implies that the private, public, and protected keywords are equally valid in either a struct definition or a class definition.

As a matter of programming style, on the other hand, if you're going to be using access modifiers, it's probably best to define your type as a class rather than as a struct. Opinions will differ on this, but IMHO the struct keyword should be used for POD (Plain Old Data) types, or for types that could be defined as structs in C.

C++ structs, strictly speaking, are very different from C structs, and are nearly identical to C++ classes. But if I see something defined in C++ as a struct, I expect (or at least prefer) it to be something similar to a C struct.

Answer 2

在 C++ 中，结构与类相同，唯一的区别是默认作用域是公共的，而私有作用域是类的默认作用域。InC访问说明符不存在，但毕竟你会用它们做什么？

Answer 3

是的，您可以在 C++ 结构中使用public, protectedin 。private

不，C 中不存在访问修饰符。

class在 C++ 中，和之间的唯一区别struct是 a 的成员class是默认private的，而 a 的成员struct是默认的public。这意味着 C++struct可以具有成员函数、构造函数、重载运算符并使用class.

Answer 4

struct与c ++中没有太大区别class。默认可见性是公开的而不是私有的。C 不支持这些。

Answer 5

我们可以在 c++ 的结构中使用访问说明符 - 私有的和受保护的吗？

是的。Astruct是一个类；唯一的区别是如果您未指定默认可访问性（ publicforstruct和privatefor ）。class

C语言也允许使用访问修饰符吗？访问说明符真的存在于 C 中吗？

不，C 没有访问说明符。

Answer 6

C++ 中astruct和 a的唯一区别是 a的成员是默认的，而 a的成员是默认的。您可以在它们中使用访问说明符，就像您可以在它们中使用其他任何东西一样。classstructpublicclassprivate

C 中没有访问说明符。