What is char ** in C? [duplicate]

Question

Possible Duplicate:
What is double star?

I am fairly new to C, and have come across this statement

typedef char **TreeType

I have a pretty good idea of what typedef does, but I have never seen char** before. I know that char* is a char array or similiar to a string. Im not sure if char** is a 2d char array or if it is the pointer to a character array. I have looked around but cannot find what it is. If you could please explain what a char** is or point me in the right direction it would be very much appreciated.

Thanks! :)

Answer 1

Technically, the char* is not an array, but a pointer to a char.

Similarly, char** is a pointer to a char*. Making it a pointer to a pointer to a char.

C and C++ both define arrays behind-the-scenes as pointer types, so yes, this structure, in all likelihood, is array of arrays of chars, or an array of strings.

Answer 2

It is a pointer to a pointer, so yes, in a way it's a 2D character array. In the same way that a char* could indicate an array of chars, a char** could indicate that it points to and array of char*s.

Answer 3

well, char * means a pointer point to char, it is different from char array.

char amessage[] = "this is an array";  /* define an array*/
char *pmessage = "this is a pointer"; /* define a pointer*/

And, char ** means a pointer point to a char pointer.

You can look some books about details about pointer and array.