c++ - C-strings null 终止字符 \0 修改

Question

C 字符串末尾的空字符是否始终为常量且无法修改？意思是，程序员可以修改 C 字符串末尾的空字符 /0 吗？或者它是恒定的并且不能被移除。示例：'Steak' 在 cstring 中，它在位置 5 处有 \0。当 'steak' 被修改时，我们可以完全删除 \0 吗？

Answer 1

C 字符串末尾的空字符是否始终为常量且无法修改？

如果我们谈论的是字符数组（静态或动态），则否，但如果您指的是常量字符串文字，则可以，例如：

const char* str = "steak";

程序员可以修改 C 字符串末尾的空字符 /0 吗？

是的，只要内存不是只读的。

我们可以完全删除 \0 吗？

是的。但是，如果您将此字符串与期望的函数一起使用'\0'，则行为未定义

Answer 2

If the C-string is the return value of the c_str() or data() member functions of std::string, then the standard forbids the modification of the trailing 0 element. Of course, just because the standard forbids it doesn't mean that anything in C++ or its runtime environment will warn you about the violation. It's quite possible that you can write code which attempts to modify the trailing 0, and it will execute without raising any alarms. However, it is also very likely that things will go wrong in unpredictably strange ways.

So don't do it.