How to declare a pointer to a character array in C?

Question

How do I declare a pointer to a character array in C?

Bushnell

I'm tempted to say something snarky like "Read the assigned chapter"... in any event, you need more information: language? overall objective? context? This doesn't seem to meet the bar of expectation of questions on this site. – Drifter

Do you really want a pointer to an array? Or a pointer to the first element of an array? Do you know about cdecl? – Phocine

To expand a bit on Carl's point: a pointer to an array is possible, but rarely (oh, so very rarely) needed or wanted. Most of the time, you want a pointer to (often const) char. – Unsuspected

Thanks for answering @CarlNorum , the funny part is I was expecting the respective page from cplusplus.com, but this outranked it, which is good because know I know about cdecl! – Delaminate

@JerryCoffin "~rarely (oh, so very rarely) needed or wanted" are you talking in the C++ application or C? I thought int main (int argc, char** argv) is common in the C (char** argv is an example of the pointer to the array). – Confession

@CloudCho: that's a pointer to a pointer, which happens to refer to the initial element of an array--but it still doesn't have type "pointer to array". – Unsuspected

The pointer isn't the array of character, for example, argv[0] = "main.cpp" in C language? – Confession

Answer 1

I guess I'll give this answer in parts:

1. Here's a pointer to an array of chars (I assumed a 10-element array):

   char (*x)[10];
   

   Let's break it down from the basics:

   x
   

   is a pointer:

   *x
   

   to an array:

   (*x)[10]
   

   of chars:

   char (*x)[10]
   

2. However, most of the time you don't really want a pointer to an array, you want a pointer to the first element of an array. In that case:

   char a[10];
   char *x = a;
   char *y = &a[0];
   

   Either x or y are what you're looking for, and are equivalent.

3. Tip: Learn about cdecl to make these problems easier on yourself.

Phocine

@Carl I think you've missed some asterisks in item 2 – Arteriosclerosis

Yup - most definitely. Thanks, @sidyll! If you see me do that in the future, feel free to edit them in yourself - it seems you have plenty of rep to do so. – Phocine

Well, I just didn't want to break the integrity of the answer from a user for whom I have great respect! – Arteriosclerosis

Answer 2

You can declare it as extern char (*p)[];, but it's an incomplete type. This is of course because C has no "array" type generically that is a complete type; only arrays of a specific size are complete types.

The following works:

extern char (*p)[];

char arr[20];

char (*p)[20] = &arr;  // complete type now: p points to an array of 20 chars

Chaqueta

Answer 3

I could suggest...

Declaration is:
char* array;

And then definition is:
array = "James Bond";

To print out:
printf ("%s \n", array);

Some programmers probably mention the above code isn't memory safe or the definition is actually re assignment, so

char* array = "James Bond";

would be a general practice.

Confession