C++ : Meaning of const char*const*

Question

在其中一个 C++ 程序中，我看到了一个函数原型(prototype):int Classifier::command(int argc, const char*const* argv)

const char*const* argv 是什么意思？和 const char* argv[] 一样吗？const char** argv 也一样吗？

Answer 1

来自 C++ Super-FAQ :

Read the pointer declarations right-to-left.

• const X* p means "p points to an X that is const": the X object can't be changed via p.
• X* const p means "p is a const pointer to an X that is non-const": you can't change the pointer p itself, but you can change the X object via p.
• const X* const p means "p is a const pointer to an X that is const": you can't change the pointer p itself, nor can you change the X object via p.

And, oh yea, did I mention to read your pointer declarations right-to-left?

const char * const *与 char const * const * 相同: 一个(非 const)指针，指向一个指向 const char 的 const 指针。

const char *与 char const * 相同: 一个指向 const char 的(非 const)指针。

const char * *与 char const * * 相同: 一个(非常量)指向一个(非常量)指向一个常量字符的指针。