Dica: convertendo qualquer tipo de variável para String

Dica extraída do site: http://www.delphi3000.com/articles/article_1540.asp

function ToString(Value: Variant): String;
begin
  case TVarData(Value).VType of
    varSmallInt,
    varInteger   : Result := IntToStr(Value);
    varSingle,
    varDouble,
    varCurrency  : Result := FloatToStr(Value);
    varDate      : Result := FormatDateTime('dd/mm/yyyy', Value);
    varBoolean   : if Value then Result := T else Result := F;
    varString    : Result := Value;
    else           Result := ;
  end;
end;


Use:

ShowMessage(ToString(10.87));
ShowMessage(ToString(10));