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From: bokiteam on 3 Mar 2006 03:11
Hi All,

Here is the declaration I can't understand:

APattern_t * * gStatePatterns ; /*the array of pointers to the
state patterns */

// this is pointer's pointer? why we need this ?

Here is the APattern_t's define:

typedef struct APatternTag
{

.....
......

}APattern_t ;

BR/
Boki.

From: Jim Langston on 3 Mar 2006 03:40

<bokiteam(a)ms21.hinet.net> wrote in message
news:1141373509.420868.190630(a)p10g2000cwp.googlegroups.com...
> Hi All,
>
> Here is the declaration I can't understand:
>
> APattern_t * * gStatePatterns ; /*the array of pointers to the
> state patterns */
>
> // this is pointer's pointer? why we need this ?
>
> Here is the APattern_t's define:
>
> typedef struct APatternTag
> {
>
> ....
> .....
>
> }APattern_t ;
>
> BR/
> Boki.

A pointer to a pointer is typically used as a pointer to an array of
pointers. A very good example of this is the typical definition of main:

int main( int argc, char **argv )
{
}

argv is used as an array of character pointers. So argv[0] would be a
pointer to an array of characters (c style string, null terminated character
array). argv[1] would be another pointer to an array of characters.

Look at how gStatePatters and you'll probably find it being treated as an
array of pointers.


From: bokiteam on 3 Mar 2006 03:43
Got it!

Thank you very much!

BR/
Boki.

Jim Langston wrote:
> <bokiteam(a)ms21.hinet.net> wrote in message
> news:1141373509.420868.190630(a)p10g2000cwp.googlegroups.com...
> > Hi All,
> >
> > Here is the declaration I can't understand:
> >
> > APattern_t * * gStatePatterns ; /*the array of pointers to the
> > state patterns */
> >
> > // this is pointer's pointer? why we need this ?
> >
> > Here is the APattern_t's define:
> >
> > typedef struct APatternTag
> > {
> >
> > ....
> > .....
> >
> > }APattern_t ;
> >
> > BR/
> > Boki.
>
> A pointer to a pointer is typically used as a pointer to an array of
> pointers. A very good example of this is the typical definition of main:
>
> int main( int argc, char **argv )
> {
> }
>
> argv is used as an array of character pointers. So argv[0] would be a
> pointer to an array of characters (c style string, null terminated character
> array). argv[1] would be another pointer to an array of characters.
>
> Look at how gStatePatters and you'll probably find it being treated as an
> array of pointers.

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