extern declaration, T* v/s T[]

Question

I saw following piece of code in a legacy project.

/* token.c */
struct token id_tokens[MAX_TOKENS];

/* analyse.c (v1) */
extern struct token *id_tokens; /*         


        

Answer 1

lets understand same stuff by program

test.c

#include
#include"head.h"
struct token id_tokens[10];
int main()
{
printf("In original file: %p",id_tokens);
testing();
}

head.h

struct token {
int temp;
};

---

test1.c with v1

#include
#include"head.h"
extern struct token* id_tokens;
void testing () {
printf("In other file %p",id_tokens);
}

Output : In original file: 0x601040In other file (nil)

---

test1.c with v2

#include
#include"head.h"
extern struct token id_tokens[];
void testing () {
printf("In other file %p",id_tokens);
}

Output : In original file: 0x601040In other file 0x601040

---

This clearly shows that v1 is not correct and v2 is correct.