returning pointer to a pointer in c

Question

I'm trying to return a pointer to a pointer from a function.

I have the following function

char **foo() {
 const char **bar;
 ...
 return bar;
}

and I get the following warning:

warning: return from incompatible pointer type [enabled by default]

what am I missing?

Answer 1

You can't jsut cast away the const qualifier like that. It points to pointers to const chars. You can however:

 const char **foo() {
   const char **bar;
   ...
   return bar;
  }

Answer 2

bar被声明为const char **但是您将返回char **

Answer 3

这是因为函数foo返回char ** ，而bar是const char **类型。