[fpc-pascal] Array clearing

[Sven Barth]

Am 04.04.2017 13:55 schrieb "Ryan Joseph" <ryan at thealchemistguild.com>:
>
>
> > On Apr 4, 2017, at 4:58 PM, Howard Page-Clark via fpc-pascal <
fpc-pascal at lists.freepascal.org> wrote:
> >
> > You can always use FillChar and its kin on specific 'nested' arrays
like this
> >
> > type
> >  TIntArray = array of Integer;
> >  TIntIntArray = array of TIntArray;
> >  TIntIntIntArray = array of TIntIntArray;
> >
> >  procedure FillArray(const anArray: TIntIntIntArray; aValue: DWord);
> >  var
> >    x, y: integer;
> >  begin
> >    for x:=0 to High(anArray) do
> >      for y:=0 to High(anArray[x]) do
> >        FillDWord(anArray[x][y][0], Length(anArray[x][y]), aValue);
> >  end;
>
> Doesn’t iterating the array default the purpose of FillChar? The goal was
the most efficient way clear the array with zero’s. Even if the array if
nested 3 levels deep (anArray[x][y][z]) it should (I hope) be a contiguous
block of memory that was allocated (correct me if I wrong please).
>

As I wrote that isn't the case. Each dynamic array is allocated
independently (and thus you could also resize each subelement
independently).

If you want continuous memory areas you need to use static arrays or
develop your own dynamic data structure that uses array properties.

Regards,
Sven
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