* Octal Conversion in VB @ 2003-09-07 15:30 chrissy 2003-09-07 16:08 ` Ludovic Brenta 0 siblings, 1 reply; 6+ messages in thread From: chrissy @ 2003-09-07 15:30 UTC (permalink / raw) I was playing around in VB trying to come up with a simple application to convert entered strings of alphanumerics into octal numbers. I took the approach of declaring a series of variables as integers, and calling the library functions "Val" and "Str" to handle the data conversions from the text box I was using to key in the alphanumerics and to the text box I was assigning the resulting string. I then wrote a series of expressions to assign values to each of the declared variables, in sequence. I then concatenated the resultant character string to produce the number sequence. Thus: Private Sub cmdConvert_Click() Dim A, B, C, D as Integer A = Val(txtDecimal.Text) B = A Mod 8 C = A \ 8 Mod 8 D = A \ (8 ^ 2) txtOctal.Text = Str(D) + Str (C) + Str (B) End Sub This seemed to work, but the code looked ugly, and I'm not sure a truth table would support the conversion to infinity. Am I right? Is there a better and tidier way? Hoping for some guidance Chrissy ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Octal Conversion in VB 2003-09-07 15:30 Octal Conversion in VB chrissy @ 2003-09-07 16:08 ` Ludovic Brenta 2003-09-07 20:14 ` Robert I. Eachus 0 siblings, 1 reply; 6+ messages in thread From: Ludovic Brenta @ 2003-09-07 16:08 UTC (permalink / raw) chrissy_brady1@yahoo.com (chrissy) writes: > I was playing around in VB trying to come up with a simple application ^^^^^^ See, comp.lang.ada? This illustrates my earlier point about disposable developers and disposable software. Chrissy, this is not against you, but why do you want a "simple" application? Is it not better to write a "correct" and "maintainable" application instead? > to convert entered strings of alphanumerics into octal numbers. > > This seemed to work, but the code looked ugly, and I'm not sure a > truth table would support the conversion to infinity. Am I right? > > Is there a better and tidier way? > > > Hoping for some guidance Here is a general algorithm that does what you want. Note that you need some mathematical background to understand why there are log(N)/log(8) octal digits in any integer number. HTH -- Ludovic Brenta. with Ada.Text_IO; use Ada.Text_IO; with Ada.Integer_Text_IO; use Ada.Integer_Text_IO; with Ada.Numerics.Elementary_Functions; use Ada.Numerics.Elementary_Functions; procedure Decimal_To_Octal is function Read_Number return Integer is S : String (1 .. 100); Last : Natural; Result : Integer; begin Get_Line (S, Last); Get (From => S (1 .. Last), Item => Result, Last => Last); return Result; end Read_Number; Number_To_Convert : Integer := Read_Number; begin Put (Item => Number_To_Convert); -- First print it as decimal Put (Item => Number_To_Convert, Base => 8); -- Print as octal. Put_Line; -- An alternative that doesn't use the Ada representation for octals: declare Number_Of_Digits : constant Integer := 1 + Integer (Log (Float (Number_To_Convert)) / Log (8.0)); Octal_Digits : array (1 .. Number_Of_Digits) of Integer := (others => 0); begin for I in reverse Octal_Digits'Range loop Octal_Digits (I) := Number_To_Convert mod 8; Number_To_Convert := Number_To_Convert / 8; end loop; -- Now loop forward to print them for I in Octal_Digits'Range loop Put (Item => Octal_Digits (I), Width => 1); end loop; end; exception when Data_Error => Put_Line ("Please input a number in decimal."); end Decimal_To_Octal; ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Octal Conversion in VB 2003-09-07 16:08 ` Ludovic Brenta @ 2003-09-07 20:14 ` Robert I. Eachus 2003-09-07 20:22 ` David C. Hoos 2003-09-08 2:46 ` chrissy 0 siblings, 2 replies; 6+ messages in thread From: Robert I. Eachus @ 2003-09-07 20:14 UTC (permalink / raw) Ludovic Brenta wrote: > Here is a general algorithm that does what you want. Note that you > need some mathematical background to understand why there are > log(N)/log(8) octal digits in any integer number. I think chrissy was actually looking to convert (ASCII?) characters into octal triplets. Something more like what follows. (I almost feel I should apolgize for all the formatting and usage code, because it tends to obscure what is going on. On the other hand, the conversion to octal not hex or decimal is chosen by the number in the line with the 8 is base comment. (Actually for decimal I'd omit the ten and change the dimensions of Temp, but that is a detail. ;-) with Ada.Text_IO; use Ada.Text_IO; with Ada.Integer_Text_IO; use Ada.Integer_Text_IO; with Ada.Command_Line; use Ada.Command_Line; procedure Octal is -- a program to convert text strings into octal. Temp: String(1..6); begin if Argument_Count /= 1 then Put_Line(" Usage: octal ""string"""); Put_Line(" If the string does not contain blanks or other special command line"); Put_Line(" characters, the parentheses may be omitted."); Set_Exit_Status(Failure); return; end if; for I in Argument(1)'Range loop if Col >= 80 then New_Line; end if; Put(Temp,Character'Pos(Argument(1)(I)),8); -- 8 is base pragma Debug(Put_Line('"' & Temp & '"')); if Temp(2) = ' ' then Temp(3..4) := "00"; elsif Temp(1) = ' ' then Temp(3) := '0'; end if; -- change leading blanks to zeros Put(' '); Put(Temp(3..5)); end loop; end Octal; with output: E:\Ada\Test>octal "This is a very long string..." octal "This is a very long string..." 124 150 151 163 040 151 163 040 141 040 166 145 162 171 040 154 157 156 147 040 163 164 162 151 156 147 056 056 056 E:\Ada\Test>octal foobar octal foobar 146 157 157 142 141 162 E:\Ada\Test>octal octal Usage: octal "string" If the string does not contain blanks or other special command line characters, the parentheses may be omitted. -- Robert I. Eachus "As far as I'm concerned, war always means failure." -- Jacques Chirac, President of France "As far as France is concerned, you're right." -- Rush Limbaugh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Octal Conversion in VB 2003-09-07 20:14 ` Robert I. Eachus @ 2003-09-07 20:22 ` David C. Hoos 2003-09-07 23:07 ` Robert I. Eachus 2003-09-08 2:46 ` chrissy 1 sibling, 1 reply; 6+ messages in thread From: David C. Hoos @ 2003-09-07 20:22 UTC (permalink / raw) "Robert I. Eachus" <rieachus@attbi.com> wrote in message news:3F5B91AA.4040203@attbi.com... <snip> > if Argument_Count /= 1 > then > Put_Line(" Usage: octal ""string"""); > Put_Line(" If the string does not contain blanks or other special > command line"); > Put_Line(" characters, the parentheses may be omitted."); > Set_Exit_Status(Failure); > return; > end if; Didn't you mean ""quotation marks" instead of "parentheses"? ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Octal Conversion in VB 2003-09-07 20:22 ` David C. Hoos @ 2003-09-07 23:07 ` Robert I. Eachus 0 siblings, 0 replies; 6+ messages in thread From: Robert I. Eachus @ 2003-09-07 23:07 UTC (permalink / raw) David C. Hoos wrote: > "Robert I. Eachus" <rieachus@attbi.com> wrote in message > news:3F5B91AA.4040203@attbi.com... > <snip> > >> if Argument_Count /= 1 >> then >> Put_Line(" Usage: octal ""string"""); >> Put_Line(" If the string does not contain blanks or other special >>command line"); >> Put_Line(" characters, the parentheses may be omitted."); >> Set_Exit_Status(Failure); >> return; >> end if; > > Didn't you mean ""quotation marks" instead of "parentheses"? > Oops! Yes. That is why code reviews are important. There are some bugs that no amount of testing can catch. ;-) -- Robert I. Eachus "As far as I'm concerned, war always means failure." -- Jacques Chirac, President of France "As far as France is concerned, you're right." -- Rush Limbaugh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Octal Conversion in VB 2003-09-07 20:14 ` Robert I. Eachus 2003-09-07 20:22 ` David C. Hoos @ 2003-09-08 2:46 ` chrissy 1 sibling, 0 replies; 6+ messages in thread From: chrissy @ 2003-09-08 2:46 UTC (permalink / raw) "Robert I. Eachus" <rieachus@attbi.com> wrote in message news:<3F5B91AA.4040203@attbi.com>... > Ludovic Brenta wrote: > > > Here is a general algorithm that does what you want. Note that you > > need some mathematical background to understand why there are > > log(N)/log(8) octal digits in any integer number. > > I think chrissy was actually looking to convert (ASCII?) characters into > octal triplets. Something more like what follows. I actually wanted to produce a string of alphanumerics representing the integer value of a Base 10 integer, converted to Base 8. Thus the ASCII string entered to a text box in VB "94" ultimately returns the string "136". Thanks so much for the suggestion. It's ingenious, but I'm stuck with VB for the moment. Another friend suggested the following for VB: Dim DecimalStr As String Dim OctalStr As String Dim HexadecimalStr As String DecimalStr = InputBox ("Enter decimal value") OctalStr = Oct$(DecimalStr) HexadecimalStr = Hex$(DecimalStr) MsgBox (OctalStr) MsgBox (HexadecimalStr) As a safety mechanism to avoid problems with null values, you could use these lines instead of the corresponding ones above: OctalStr = Oct$(DecimalStr & " ") HexadecimalStr = Hex$(DecimalStr & " ") This of course does much more than I'd asked, as it's handling hexadecimals as well. The same friend also offered me a solution in Pascal: I've attached a generic base conversion program in Pascal for bases from 2 to 36 but there's no error handling. These are fairly standard algorithms. The programing term is 'cliches'. It converts from any base to any base. Louie. ----------------------------------------------------------------------------- Tabs set to 4 spaces { baseconvert.pas - Base convertor of integers Luis Esteban 8 September 2003 Created without error checking } program BaseConvertor (input, output); var InputNumber : string; OutputNumber : string; InputBase : integer; OutputBase : integer; Value : longint; function StringToInteger (Number : string; Base : integer) : longint; var Accumulator : longint; i : integer; begin Accumulator := 0; for i := 1 to Length(Number) do begin {writeln ('Number[', i:1, '] = ', Number[i]);} if Number[i] in ['0'..'9'] then begin Accumulator := Accumulator * Base + (ord(Number[i]) - ord('0')); end else if Number[i] in ['A'..'Z'] then begin Accumulator := Accumulator * Base + (10 + ord(Number[i]) - ord('A')); end else if Number[i] in ['a'..'z'] then begin Accumulator := Accumulator * Base + (10 + ord(Number[i]) - ord('a')); end else begin writeln ('Ignoring ''', Number[i], ''''); end; end; StringToInteger := Accumulator; end; function ReverseString (s : string) : string; var i : integer; t : string; begin t := ''; for i := Length(s) downto 1 do begin t := t + s[i]; end; ReverseString := t; end; function IntegerToString (Number : longint; Base : integer) : string; var r : string; NewDigit : integer; begin r := ''; while Number > 0 do begin NewDigit := Number mod Base; if NewDigit < 10 then begin r := r + chr(NewDigit+ord('0')); end else if NewDigit < 36 then begin r := r + chr(NewDigit+ord('A')-10); end; Number := Number div Base; end; IntegerToString := ReverseString (r); end; begin write ('Enter number: '); readln (InputNumber); write ('Enter input base: '); readln (InputBase); write ('Enter output base: '); readln (OutputBase); writeln; Value := StringToInteger(InputNumber, InputBase); OutputNumber := IntegerToString(Value, OutputBase); writeln (InputNumber,'(',InputBase,') = ',Value,'(10) = ',OutputNumber,'(',OutputBase,')'); end. Again this is more than I'd asked for. I'm so impressed with the software community. You guys are just so generous!! With Lots of Thanks and other Sincere signals of fratitude Chrissy ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-09-08 2:46 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2003-09-07 15:30 Octal Conversion in VB chrissy 2003-09-07 16:08 ` Ludovic Brenta 2003-09-07 20:14 ` Robert I. Eachus 2003-09-07 20:22 ` David C. Hoos 2003-09-07 23:07 ` Robert I. Eachus 2003-09-08 2:46 ` chrissy
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