c++ - 为什么数据成员在 C++ 中默认是私有(private)的？

Question

在 C++ 中类中的所有数据成员在默认情况下都是私有(private)的是否有任何特殊原因？

Answer 1

The Design and Evolution of C++

2.10 保护模型

Before starting work on C with Classes, I worked with operating systems. The notions of protection from the Cambridge CAP computer and similar systems - rather than any work in programming languages - inspired the C++ protection mechanisms. The class is the unit of protection and the fundamental rule is that you cannot grant yourself access to a class; only the declarations placed in the class declaration (supposedly by its owner) can grant access. By default, all information is private.