const vs non-const

最新推荐文章于 2024-08-06 12:36:43 发布

chuwachen

最新推荐文章于 2024-08-06 12:36:43 发布

阅读量581

点赞数

CC 4.0 BY-SA版权

分类专栏： C++ 文章标签： function

本文链接：https://blog.youkuaiyun.com/chuwachen/article/details/7452953

12 篇文章

订阅专栏

本文探讨了在编程中变量与函数之间的类型匹配原则，详细解释了常量和非常量变量如何与常量和非常量函数进行交互。通过实例展示了指针和对象在不同场景下的使用方式。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

It is OK to pass a non-const variable to a function with const parameter; it is incorrect to pass a const variable to a function with non-const parameter.
non-const function can invoke const function; const function can't invoke non-const function.
A* const a // const pointer, non-const object; a can't point to other objects, but the object that it points can be changed.
- A aa;
- *a = aa; // ok because *a is non-const object.
- a can call non-const function in class A.
- a = &aa // error, because a is a const pointer.
const A* a // non-const pointer, const object; a can point to other objects, but the object that it points can't be changed.
- A aa;
- *a = aa; // error, because *a is a const object.
- a can't call non-const function in class A.
- a = &aa // ok, because a is a non-const pointer.
STL iterators are similar to pointer.
- xxx::iterator is equal to T*
- const xxx::iterator is equal to T* const
- xxx::const_iterator is equal to const T*