C# Discussion Boards - CodeProject

PIEBALDconsult22-Jan-09 19:45

22-Jan-09 19:45

Ew, but yeah it may come to that. There's still gotta be a better way.

PIEBALDconsult22-Jan-09 19:24

22-Jan-09 19:24

It seems that the word "octal" doesn't appear anywhere in the C# spec.

Luc Pattyn22-Jan-09 21:18

22-Jan-09 21:18

there are no "binary" or "hex" leywords either, but that doesn't stop us from using whatever we want as a number base.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Good riddance W

modified on Friday, June 10, 2011 12:04 PM

CPallini23-Jan-09 1:40

23-Jan-09 1:40

As a matter of fact, I use beer as number base. Roll eyes | :rolleyes:

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Luc Pattyn23-Jan-09 2:02

23-Jan-09 2:02

That won't cut it. Nobody would trust you dealing with beer-based numbers.
The way I know you, you would soon prove infinity does not exist. Laugh | :laugh:

Luc Pattyn [Forum Guidelines] [My Articles]

Good riddance W

CPallini23-Jan-09 2:09

23-Jan-09 2:09

Actually, I'm trying to reach infinity, but......... hic! ........... another one, plz plz!
Big Grin | :-D

PIEBALDconsult23-Jan-09 6:24

23-Jan-09 6:24

Absolutely, great for bubble sorts without the expense that champagne incurs or the sugary-sweetness of cola.

PIEBALDconsult23-Jan-09 4:29

23-Jan-09 4:29

No, but the words appear in the spec, as in:

binary-operator-declarator:
type   operator   overloadable-binary-operator   (   type   identifier   ,   type   identifier   )
 
 
decimal-integer-literal:
decimal-digits   integer-type-suffixopt
 
hexadecimal-integer-literal:
0x   hex-digits   integer-type-suffixopt
0X   hex-digits   integer-type-suffixopt

Not so for octal.

Luc Pattyn23-Jan-09 4:48

23-Jan-09 4:48

Actually, binary operators is a misnomer IMO; it really are bit-level operators meaning all the bits have independent meaning and behavior, there is no link to base 2 there.

I would not mind C# supporting binary and octal literals, hence also a convention to indicate those bases; and support for it in TryParse and ToString.

However I would very rarely use it; octal is thing of the past; some instruction sets got described in octal (e.g. PDP8 and PDP11), which looked OK at the time mainly because they had 8 registers so it was a signle digit that chose the register).

Binary notation tends to lack compactness; with a comma every 4 bits, an Int32 would take 39 characters.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Good riddance W

modified on Friday, June 10, 2011 12:05 PM

PIEBALDconsult23-Jan-09 5:20

23-Jan-09 5:20

Luc Pattyn wrote:
binary operators

... operate on two operands. You know that.

Luc Pattyn wrote:
supporting binary and octal literals

The C way of indicating octal literals is problematic. C# leaves it out, but that means that code copied from C will be broken with no alert.

I expect 0o10 would be better, with a warning if someone uses a capital O rather than a lowercase o, as with the l to indicate long.

Luc Pattyn wrote:
octal is thing of the past

Yes, the only time I need octal is for OpenVMS UICs, and I still do see why they have to be done in octal.

Luc Pattyn wrote:
Binary notation tends to lack compactness

Yeah, gimme Base-64 any day! Big Grin | :-D

Luc Pattyn23-Jan-09 5:27

23-Jan-09 5:27

PIEBALDconsult wrote:
binary operators
... operate on two operands. You know that.

Yeah, I used to known that (seems like the flu is not really helping me);
"binary operators" too is unrelated to base 2.

and bit-wise operators it the right term for some of the (mostly binary) operators Laugh | :laugh:

Luc Pattyn [Forum Guidelines] [My Articles]

Good riddance W

modified on Friday, June 10, 2011 12:05 PM

dan!sh 22-Jan-09 21:19

dan!sh

22-Jan-09 21:19

C# does not have octal literals(unfortunately). But we do have it in VB. So you have two ways:
1. Create a VB dll and refer it C#.
2. Get the data in string and write your own method to convert it to Octal.

The word "politics" describes the process so well: "Poli" in Latin meaning "many" and "tics" meaning "bloodsucking creatures."

जय हिंद

I think your function is 'ugly'

musefan22-Jan-09 22:31

musefan

22-Jan-09 22:31

how bout:

public int Oct(int dec)
{
return ((dec / 8) * 10) + (dec % 8);
}

then

int octal = Oct(8);//should result in 10

CPallini23-Jan-09 1:51

Re: I think your function is 'ugly' [modified]

23-Jan-09 1:51

The reason:

We are dealing with number representaion in a given base, hence the function should return a string, not an integer.
What if the input is 64 instead of 8?

PIEBALDconsult23-Jan-09 8:28

Re: I think your function is 'ugly'

23-Jan-09 8:28

CPallini wrote:
should return a string

I disagree. Given a binary representation of 10-base10 [00001010], I want to get a binary representation of 10-base8 [00001000].

I'd rather not have to convert to string and back to do that, but I see no other way currently. And it may prove to be more efficient that way anyway.

Edit:

Or more clearly; in C, the statement int x = 010 ; results in a variable that contains the value eight, but in C# the result is the value ten.
It is desirable, in some cases, for int x = Oct ( 010 ) ; (or some such syntax) in C# to produce the desired value of eight, hopefully at compile-time as is the case in C (and apparently in VB.net).

modified on Friday, January 23, 2009 3:52 PM

CPallini23-Jan-09 10:55

Re: I think your function is 'ugly'

23-Jan-09 10:55

You are talking about literals [^] (and you would like octal ones).

I still consider his proposed function conceptually (and technically) wrong.
Smile | :)

PIEBALDconsult23-Jan-09 12:50

23-Jan-09 12:50

CPallini wrote:
You are talking about literals

Ah, you're catching on. Big Grin | :-D

CPallini wrote:
conceptually (and technically) wrong

Oh, absolutely, but

public static int
Oct
(
    int Value
)
{
    return ( System.Convert.ToInt32 ( Value.ToString() , 8 ) ) ;
}

just seems dirty (but not as dirty as resorting to VB).

Luc Pattyn23-Jan-09 1:59

23-Jan-09 1:59

musefan wrote:
public int Oct(int dec)
{
return ((dec / 8) * 10) + (dec % 8);
}

That does not make sense whatsoever. An integer number has one value, and it does not know anything about bases. Five is five, ten is ten.

It is only when you want to perform (mostly human) I/O that you need conversion to/from a string, and that is where the notion of base, and some conventions about how to indicate such base, come into play.

A nasty result of your way is arithmetic starts to fail pretty soon:

int decimal5=5;
int octal5=Oct(decimal5);   // returns 5
int decimal12=12;
int octal12=Oct(decimal12); // returns the value of fourtheen
int octalSum=octal5+octal12;
Console.WriteLine(octalSum); // prints "19" i.e. uses invalid characters in the octal world.

The bormal thing to do to get it work correctly all the time is using integers without caring about base, except for when you perform input/output. Hence:

int five=ReadAnOctalNumberFromConsole();  // let's assume you enter 5
int twelve=12;
int sum=five+twelve;
WriteToConsoleUsingOctal(sum); // prints "21"

So you would have to come up with two methods.

There is one laborious alternative, very bad for performance: you could implement all arithmetic yourself, and always operate on strings, as in:

string five="5";
string twelve="12";
string sum=OctalStringArithmetic.Add(five, twelve);
Console.WriteLine(sum); // prints "21" if you did it well

[ADDED] Addition in strings is easy, multiplication is harder; division, square root, and
all transcendentals are rather hard to do.[/ADDED]

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Good riddance W

modified on Friday, January 23, 2009 8:11 AM

modified on Friday, June 10, 2011 12:06 PM

PIEBALDconsult23-Jan-09 5:22

23-Jan-09 5:22

Will that only work with one- and two-digit octal values?

P.S. And I would expect that to work as Oct ( 10 ) yields 8

modified on Friday, January 23, 2009 12:29 PM

musefan26-Jan-09 0:31

musefan

26-Jan-09 0:31

OK forget my attemp, it does not work after 63(DEC)

But to say it has to be a string is wrong, it all depends what you want to do with the result

DaveyM6923-Jan-09 0:11

DaveyM69

23-Jan-09 0:11

There is no octal (or binary) literal in C#. I rolled my own in this article[^].

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

creating dll

lawrenceinba22-Jan-09 17:58

lawrenceinba

22-Jan-09 17:58

hi friends

how to create dll(dynamic link library) for user developed projects

the quieter u become more u hear

Re: creating dll

PIEBALDconsult22-Jan-09 18:54