I'm having a bit of a problem when trying to do the following.

Here's the pseudo-code
**************************
int main()
{
Mobile NPC[2] = new Mobile;

NPC[0].GivenName[]  = "Some         ";
NPC[0].FamilyName[] = "Name         ";
NPC[0].NickName[]   = "Random NPC   ";

NPC[1].GivenName[]  = "Medusa       ";
NPC[1].FamilyName[] = "Gorgon       ";
NPC[1].NickName[]   = "Beheaded Lady";

PC.PrintInfo();
NPC[0].PrintInfo();
NPC[1].PrintInfo();
return 0;
}
**************************

And here's the output I'd get from it.
**************************
Name: Medusa        Gorgon
Nick: Beheaded Lady

Name: Medusa        Gorgon
Nick: Beheaded Lady
**************************

What kind of approach I'd need to use for NPC[0] and NPC[1] to be treated as two separated entities, thus enabling me to create as much class instances as needed at runtime?

Thanks in advance.

"Essoje Oliveira de Almeida" <Essoje_member@pathlink.com> wrote in message news:dt7nqv$2ioi$1@digitaldaemon.com...
> I'm having a bit of a problem when trying to do the following.
>
> Here's the pseudo-code
> **************************
> int main()
> {
> Mobile NPC[2] = new Mobile;
>
> NPC[0].GivenName[]  = "Some         ";
> NPC[0].FamilyName[] = "Name         ";
> NPC[0].NickName[]   = "Random NPC   ";
>
> NPC[1].GivenName[]  = "Medusa       ";
> NPC[1].FamilyName[] = "Gorgon       ";
> NPC[1].NickName[]   = "Beheaded Lady";
>
> PC.PrintInfo();
> NPC[0].PrintInfo();
> NPC[1].PrintInfo();
> return 0;
> }
> **************************
>
> And here's the output I'd get from it.
> **************************
> Name: Medusa        Gorgon
> Nick: Beheaded Lady
>
> Name: Medusa        Gorgon
> Nick: Beheaded Lady
> **************************
>
> What kind of approach I'd need to use for NPC[0] and NPC[1] to be treated
> as two
> separated entities, thus enabling me to create as much class instances as
> needed
> at runtime?
>
> Thanks in advance.
>
>

It took me a second to figure out what's going on here, but it's kind of tricky and has to do with D's array semantics.

When you define the array:

Mobile NPC[2] = new Mobile;

Something interesting happens.  NPC is a statically-sized array of length 2 (i.e. a Mobile[2]).  When you initialize it to "new Mobile," it assigns _all_ the elements of NPC to the same instance of Mobile.  Thus, NPC[0] and NPC[1] both point to the same instance of Mobile.  This is a useful feature of D's arrays as it allows you to fill an array with a single value very quickly, but in this case, it's not immediately obvious.

Instead, do

Mobile[2] NPC;
foreach(inout Mobile m; NPC)
    m = new Mobile;

That will create a new instance of Mobile for each element in NPC.  Notice the "inout" in the foreach loop; that makes it so you can modify the contents of NPC inside the foreach loop through the variable m.  This is equivalent to

for(int i = 0; i < NPC.length; i++)
    NPC[i] = new Mobile;

In article <dt7r0k$2l0r$1@digitaldaemon.com>, Jarrett Billingsley says...
>
>It took me a second to figure out what's going on here, but it's kind of tricky and has to do with D's array semantics.
>
>When you define the array:
>
>Mobile NPC[2] = new Mobile;
>
>Something interesting happens.  NPC is a statically-sized array of length 2 (i.e. a Mobile[2]).  When you initialize it to "new Mobile," it assigns _all_ the elements of NPC to the same instance of Mobile.  Thus, NPC[0] and NPC[1] both point to the same instance of Mobile.  This is a useful feature of D's arrays as it allows you to fill an array with a single value very quickly, but in this case, it's not immediately obvious.
>
>Instead, do
>
>Mobile[2] NPC;
>foreach(inout Mobile m; NPC)
>    m = new Mobile;
>
>That will create a new instance of Mobile for each element in NPC.  Notice the "inout" in the foreach loop; that makes it so you can modify the contents of NPC inside the foreach loop through the variable m.  This is equivalent to
>
>for(int i = 0; i < NPC.length; i++)
>    NPC[i] = new Mobile;

I see. That did clear up things for me, thank you very much. :)