[svlug] abt arrays in C

[Erik Fears]

On Wed, Apr 02, 2003 at 06:40:44PM -0800, R Balaji wrote:
> Hi,
> Pardon me as this mail as nothing to do with Linux.
> I have a simple C programming doubt.
> 
> void main(){
> 
> int b[10];
> ____ = procedure();
> 
> }
> 
> ____ procedure(){
> 
> int a[10];
> return _____;
> }
> 
> I want to return array a from procedure () to array b
> in main. So please fill up the blanks. (____)
> 
> Thanks
> Balaji.R
>

As matt pointed out, the only way to do this would be with malloc
(or a static array, but then you could only return one value at once).

Then you return a pointer to the memory you just created.


BAD:

type *proc()
{
   type ret[5];

   return ret;
}

This is bad because ret (the array)'s scope is within the proc function.
Once your code executes outside of the function, the array ret becomes
garbage.


GOOD: 

type *proc()
{
   type *ret;

   ret = malloc(sizeof(type) * 5);

   return ret;
}


-Erik