This might sound stupid, but I can't access the elements of an array by using values in other array. This is the code:

int [][]g=new int[8][];

 int [8] cg=-1;
 for (int i=0;i<8;i++) {     //store random numbers between 0 & 7 in cg
  bit r;
  do {
   r=true;
   cg[i]=rand()%8;

   for (int j=0;j<i;j++)
    if (cg[i]==cg[j]) r=false;  //no repetition

  } while (!r);
 }

 int [] ord=new int[np];       //np is really bigger than 8
...
 for (int i=0;i<8;i++) {
  g[i]=new int[4];          //is there another way to do it?

  //printf("%d ",cg[i]);      //it was to check the values
  g[cg[i]][0]=ord[i];               //ERROR
 }

in the line marked ERROR I get:

Error: ArrayBoundsError

Why?? I mean, g.length (I've checked) is 8, and cg only has values between 0 and 8. So what's wrong? Oh, and if I change cg[i] for just i, it goes ok, but the result is not what I want.

-------------------------
Carlos 8294
http://carlos3.netfirms.com/

On Sat, 22 Jun 2002 21:26:50 -0500 "Carlos" <carlos8294@msn.com> wrote:

>   g[i]=new int[4];          //is there another way to do it?

This line should probably read g[cg[i]] = new int[4];

>   //printf("%d ",cg[i]);      //it was to check the values
>   g[cg[i]][0]=ord[i];               //ERROR
>  }

Since you haven't allocated g[cg[i]] yet, [0] is not a valid subscript.

"Pavel Minayev" <evilone@omen.ru> escribió en el mensaje news:CFN374305216151273@news.digitalmars.com...
> On Sat, 22 Jun 2002 21:26:50 -0500 "Carlos" <carlos8294@msn.com> wrote:
>
> >   g[i]=new int[4];          //is there another way to do it?
>
> This line should probably read g[cg[i]] = new int[4];

Why? I'm only trying to access the members of an array. They're indexed by integers, and cg[] are integers. I don't get it.

>
> >   //printf("%d ",cg[i]);      //it was to check the values
> >   g[cg[i]][0]=ord[i];               //ERROR
> >  }
>
> Since you haven't allocated g[cg[i]] yet, [0] is not a valid subscript.

Then why does it work?

void something(inout int[][]g)
{
    bit [32] p;
    for (int i=0;i<8;i++)
        p[g[i][0]]=true;
...
}

It's the same case.

On Sun, 23 Jun 2002 13:21:36 -0500 "Carlos" <carlos8294@msn.com> wrote:

>> >   g[i]=new int[4];          //is there another way to do it?
>>
>> This line should probably read g[cg[i]] = new int[4];
> 
> Why? I'm only trying to access the members of an array. They're indexed by integers, and cg[] are integers. I don't get it.

Further in your code, you use cg[i] to index g[]. Suppose i == 3,
cg[3] == 6. When you do g[i] = new int[4], you create an array,
storing it at g[3]. Then you do g[cg[i]], that is, g[6], which is
an empty array: it will only be created be when i will reach value of 6...

> Then why does it work?
> 
> void something(inout int[][]g)
> {
>     bit [32] p;
>     for (int i=0;i<8;i++)
>         p[g[i][0]]=true;
> ....
> }
> 
> It's the same case.

You mean, you do it on your array.

"Pavel Minayev" <evilone@omen.ru> escribió en el mensaje news:CFN374310422767593@news.digitalmars.com...
> On Sun, 23 Jun 2002 13:21:36 -0500 "Carlos" <carlos8294@msn.com> wrote:
>
> >
> > Why? I'm only trying to access the members of an array. They're indexed
by
> > integers, and cg[] are integers. I don't get it.
>
> Further in your code, you use cg[i] to index g[]. Suppose i == 3,
> cg[3] == 6. When you do g[i] = new int[4], you create an array,
> storing it at g[3]. Then you do g[cg[i]], that is, g[6], which is
> an empty array: it will only be created be when i will reach value of 6...
>

Thanks! It was a programming mistake. I hadn't notice that. Thanks.