Example: Multidimensional dynamic array

program project1;

type
  TArr2D = array of array of Integer;

procedure  FillArr2D(Arr: TArr2D);
var
  i, j: Integer;
begin
  for i:=Low(Arr) to High(Arr) do
    for j:=Low(Arr[i]) to High(Arr[i]) do
      Arr[i][j] := i*10 + j;
end;

procedure  ShowArr2D(Arr: TArr2D);
var
  i, j: Integer;
begin
  for i:=Low(Arr) to High(Arr) do
  begin
    Write('Arr[', i, ']:  ');
    for j:=Low(Arr[i]) to High(Arr[i]) do
      Write(Arr[i][j]:2, '  ');
    WriteLn;
  end;
end;

procedure Pause;
begin
  WriteLn;
  Write('...');
  ReadLn;
  WriteLn;
end;

var
  Arr2D: TArr2D;

begin
  SetLength(Arr2D, 5, 3);  // resize on two dimensions
    WriteLn('Rectangular dynamic array after resizing:');
    WriteLn('-----------------------------------------');
    ShowArr2D(Arr2D);
    Pause;

  FillArr2D(Arr2D);
    WriteLn('Rectangular dynamic array after filling:');
    WriteLn('-----------------------------------------');
    ShowArr2D(Arr2D);
    Pause;

  SetLength(Arr2D, 10);  // resize on one dimension
    WriteLn('Non-rectangular dynamic array after resizing on first dimension:');
    WriteLn('----------------------------------------------------------------');
    ShowArr2D(Arr2D);
    Pause;

  SetLength(Arr2D[0], 9);
  SetLength(Arr2D[1], 7);
  SetLength(Arr2D[2], 6);
  SetLength(Arr2D[3], 9);
  SetLength(Arr2D[4], 5);
  SetLength(Arr2D[5], 8);
  SetLength(Arr2D[6], 5);
  SetLength(Arr2D[7], 3);
  SetLength(Arr2D[8], 1);
  SetLength(Arr2D[9], 7);
    WriteLn('Non-rectangular dynamic array after individual resizing on second dimension:');
    WriteLn('----------------------------------------------------------------------------');
    ShowArr2D(Arr2D);
    Pause;

  FillArr2D(Arr2D);
    WriteLn('Non-rectangular dynamic array after filling:');
    WriteLn('--------------------------------------------');
    ShowArr2D(Arr2D);
    Pause;
end.

Rectangular dynamic array after resizing:
-----------------------------------------
Arr[0]:   0   0   0
Arr[1]:   0   0   0
Arr[2]:   0   0   0
Arr[3]:   0   0   0
Arr[4]:   0   0   0

...

Rectangular dynamic array after filling:
-----------------------------------------
Arr[0]:   0   1   2
Arr[1]:  10  11  12
Arr[2]:  20  21  22
Arr[3]:  30  31  32
Arr[4]:  40  41  42

...

Non-rectangular dynamic array after resizing on first dimension:
----------------------------------------------------------------
Arr[0]:   0   1   2
Arr[1]:  10  11  12
Arr[2]:  20  21  22
Arr[3]:  30  31  32
Arr[4]:  40  41  42
Arr[5]:
Arr[6]:
Arr[7]:
Arr[8]:
Arr[9]:

...

Non-rectangular dynamic array after individual resizing on second dimension:
----------------------------------------------------------------------------
Arr[0]:   0   1   2   0   0   0   0   0   0
Arr[1]:  10  11  12   0   0   0   0
Arr[2]:  20  21  22   0   0   0
Arr[3]:  30  31  32   0   0   0   0   0   0
Arr[4]:  40  41  42   0   0
Arr[5]:   0   0   0   0   0   0   0   0
Arr[6]:   0   0   0   0   0
Arr[7]:   0   0   0
Arr[8]:   0
Arr[9]:   0   0   0   0   0   0   0

...

Non-rectangular dynamic array after filling:
--------------------------------------------
Arr[0]:   0   1   2   3   4   5   6   7   8
Arr[1]:  10  11  12  13  14  15  16
Arr[2]:  20  21  22  23  24  25
Arr[3]:  30  31  32  33  34  35  36  37  38
Arr[4]:  40  41  42  43  44
Arr[5]:  50  51  52  53  54  55  56  57
Arr[6]:  60  61  62  63  64
Arr[7]:  70  71  72
Arr[8]:  80
Arr[9]:  90  91  92  93  94  95  96

...