Hey everyone,

I apologize in advance for this novice question however I'm not having
any luck finding the answer myself.

I'm attempting to loop through an array of structures passed to a
function, however I'm not sure how to obtain the number of elements in
the array.

The structure is defined as:
typedef struct {
time_t creation_date;
int priority;
char *text;
} note;

And here's the function prototype:
void get_notes(note *notes);

How would I dynamically loop through *notes?

uidzer0 <ben.lemasurier@gmail.com> wrote:

> I'm attempting to loop through an array of structures passed to a
> function, however I'm not sure how to obtain the number of elements in
> the array.

You can't. You have to pass that number in to the function, use a
terminator element, or have some other way to find out. This is the same
for all arrays, whether or not they're made of structs.

Richard

On Apr 15, 9:13am, r...@hoekstra-uitgeverij.nl (Richard Bos) wrote:
> uidzer0 <ben.lemasur...@gmail.com> wrote:
> > I'm attempting to loop through an array of structures passed to a
> > function, however I'm not sure how to obtain the number of elements in
> > the array.
>
> You can't. You have to pass that number in to the function, use a
> terminator element, or have some other way to find out. This is the same
> for all arrays, whether or not they're made of structs.
>
> Richard

Ahh... well that makes more sense - thanks.

uidzer0 wrote:
>
> I'm attempting to loop through an array of structures passed to
> a function, however I'm not sure how to obtain the number of
> elements in the array.
>
> The structure is defined as:
> typedef struct {
> time_t creation_date;
> int priority;
> char *text;
> } note;
>
> And here's the function prototype:
> void get_notes(note *notes);
>
> How would I dynamically loop through *notes?

One way is to hold the pointers to note (i.e. the note* items) in
an array terminated with a NULL. Then the function might be:

void get_notes(note *notes) {
while (*notes) {
process_one_note(*notes);
notes++;
}
}

but you would be better advised to get rid of the void and return
an error indicator. Same for process_one_note()

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home.att.net>
Try the download section.


** Posted from http://www.teranews.com **

On Tue, 15 Apr 2008 16:59:26 -0400, CBFalconer <cbfalconer@yahoo.com>
wrote:

> uidzer0 wrote:
> >
> > I'm attempting to loop through an array of structures passed to
> > a function, however I'm not sure how to obtain the number of
> > elements in the array.
> >
> > The structure is defined as:
> > typedef struct {
> > time_t creation_date;
> > int priority;
> > char *text;
> > } note;
> >
> > And here's the function prototype:
> > void get_notes(note *notes);
> >
> > How would I dynamically loop through *notes?
>
> One way is to hold the pointers to note (i.e. the note* items) in
> an array terminated with a NULL. Then the function might be:
>
OP doesn't have an array of pointers, but one pointer to an array.

> void get_notes(note *notes) {
> while (*notes) {
> process_one_note(*notes);
> notes++;
> }
> }
>
For an array of pointer you need (modulo spacing)
void get_notes (note * * notes)
then as you have it. Or (equivalent to the compiler)
void get_notes (note * notes [] )
to emphasize the array-of-pointer-ness, but downplay the fact that
array parameters/arguments are really pointers; pick your poison.

- formerly david.thompson1 || achar(64) || worldnet.att.net