Extern using pointer instead of array

Question

Suppose we have 2 files

1) file1.c

int Appples[10];

2) file2.c

extern int *Appples;

Is there any prob with this type of declaration except that i will have to handle size independently ?

@Alex Yes. If you like, I can add another answer with concrete examples and assembly code. — fuz
– fuz, Commented Jan 3, 2016 at 12:21

Marco A. · Accepted Answer · 2016-01-03 09:01:34Z

5

This is covered in C FAQs 6.1

The type pointer-to-type-T is not the same as array-of-type-T. Use extern char a[].

while this answer addresses the issue more specifically. The final point is: an array isn't a pointer and you shouldn't treat one as such.

answered Jan 3, 2016 at 9:01

Marco A.

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Comments

R Sahu · Accepted Answer · 2016-01-03 09:03:59Z

1

When you declare a variable as:

extern int *Appples;

it needs to be defined as:

int *Appples = <initializer>;

not as:

int Appples[10];

If you want to define using:

int Appples[10];

It can be declared as:

extern int Appples[10];

or

extern int Appples[];

answered Jan 3, 2016 at 9:03

R Sahu

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