DELPHI AREA Forum

Hi,

How can I remove any duplicates from a string var ?
I need auto cleaning the string from any kinde of duplicate characters.

Thanks,
Z.

What do you mean with duplicate characters? Could you please give an example?

Hi,

If the string is 'abca1231', I need the result to be 'abc123'.
Tha string is a var so I don't know what characters it will contain (user input), I just need to keep only one char of a kind.

Thanks,
Z.

Here is a solution:

Code: Select all

function RemoveDuplicateChars(const S: String): String;
var
  AlreadyVisited: array[#0..High(Char)] of Boolean;
  I: Integer;
begin
  FillChar(AlreadyVisited, SizeOf(AlreadyVisited), 0);
  Result := '';
  for I := 1 to length(S) do
  begin
    if not AlreadyVisited[S[I]] then
    begin
      Result := Result + S[I];
      AlreadyVisited[S[I]] := True;
    end;
  end;
end;