From the December 2011 Issue of Prestwood eMag

Delphi Language Details: Creating Arrays in Object Pascal By Mike Prestwood

Posted 22 years ago on 8/21/2002 and updated 3/13/2003 Take Away: This lesson shows you how to create and use several different types of arrays in Object Pascal.  Tags: Delphi , Borland Delphi , Object PASCAL , Arrays , multi-dimensional , open ended , array , create , usage , how to KB100003

Creating Arrays in Object Pascal

How to declare, set, and use values in an array:

procedure TMenuButtonForm.Button2Click(Sender: TObject);
var
ar: array[1..10] of String;
begin
ar[1] := 'David';
ar[7] := 'Young';
ShowMessage(ar[1]);
ShowMessage(ar[7]);
end;

On more example:

procedure TForm1.Button5Click(Sender: TObject);
var
  ar: Array[1..4] of String;

begin
  ar[1] := 'Lisa';
  ar[2] := 'Jane';
  ar[3] := 'Unsicker';
  ar[4] := 'Prestwood';

  ShowMessage(ar[1] + ' ' + ar[4])
  end;

Using multi-dimensional arrays

procedure TMenuButtonForm.Button3Click(Sender: TObject);
var
ar : Array[1..3, 1..2] of String;
Counter : Integer;
begin
ar[1,1] := 'Mike';
ar[1,2] := 'Prestwood';

ar[2,1] := 'David';
ar[2,2] := 'Young';

ar[3,1] := 'Phillipe';
ar[3,2] := 'Kahn';

for Counter := 1 to High(ar) do
begin
ShowMessage(ar[Counter, 1] + ' ' + ar[Counter, 2]);
end;
end;

Using 'open ended' arrays

Here is an example of a two dimensional resizable dynamic array:

procedure TMenuButtonForm.Button4Click(Sender: TObject);
var
ar : Array of Array of String;
Counter : Integer;
begin
SetLength(ar, 3, 3); //This sets the size.
ar[0,1] := 'Mike';
ar[0,2] := 'Prestwood';

ar[1,1] := 'David';
ar[1,2] := 'Young';

ar[2,1] := 'Phillipe';
ar[2,2] := 'Kahn';

for Counter := Low(ar) to High(ar) do
begin
ShowMessage(ar[Counter, 1] + ' ' + ar[Counter, 2]);
end;
end;

Comments

KB Post Contributed By Mike Prestwood:

Mike Prestwood is a drummer, an author, and creator of the PrestwoodBoards online community. He is the President & CEO of Prestwood IT Solutions. Prestwood IT provides Coding, Website, and Computer Tech services. Mike has authored 6 computer books and over 1,200 articles. As a drummer, he maintains play-drums.com and has authored 3 drum books. If you have a project you wish to discuss with Mike, you can send him a private message through his PrestwoodBoards home page or call him 9AM to 4PM PST at 916-726-5675 x205. Visit Profile