Hexadecimal to Binary

[=?Utf-8?B?VHJlY2l1cw==?=]

Hello, Newsgroupians:

I've a question regarding Hexadecimal to binary conversion.

Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string. How can I accomplish this with minimal code? I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).

EXA:

string str = "FA38";
string binStr = SomeClass.Hex2B in(str);

This would produce the following output...

"11111010001110 00"


Thank you,


Trecius

[Jon Skeet [C# MVP]]

Re: Hexadecimal to Binary

Trecius <Trecius@discus sions.microsoft .comwrote:

I've a question regarding Hexadecimal to binary conversion.
>
Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string. How can I accomplish this with minimal code? I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).
>
EXA:
>
string str = "FA38";
string binStr = SomeClass.Hex2B in(str);
>
This would produce the following output...
>
"11111010001110 00"

Given that there are only 16 hex digits, and each hex digit maps to
exactly 4 characters, it's relatively straightforward . There are no
doubt ways to do it with shorter code than this, but this way is pretty
simple:


using System;
using System.Text;

class Test
{
static void Main()
{
string binStr = HexToBin("FA38" );
Console.WriteLi ne(binStr);
}

static readonly string[] Nybbles =
{"0000", "0001", "0010", "0011",
"0100", "0101", "0110", "0111",
"1000", "1001", "1010", "1011",
"1100", "1101", "1110", "1111"};
static string HexToBin(string input)
{
StringBuilder builder = new StringBuilder(i nput.Length*4);
foreach (char c in input)
{
if (c >= '0' && c <='9')
{
builder.Append( Nybbles[c-'0']);
}
else if (c >= 'a' && c <= 'f')
{
builder.Append( Nybbles[c-'a'+10]);
}
else if (c >= 'A' && c <= 'F')
{
builder.Append( Nybbles[c-'A'+10]);
}
else
{
throw new FormatException ("Invalid hex digit: "+c);
}
}
return builder.ToStrin g();
}
}

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon_skeet
C# in Depth: http://csharpindepth.com

[Jeroen Mostert]

Re: Hexadecimal to Binary

Trecius wrote:

I've a question regarding Hexadecimal to binary conversion.
>
Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string. How can I accomplish this with minimal code? I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).
>
EXA:
>
string str = "FA38";
string binStr = SomeClass.Hex2B in(str);
>
This would produce the following output...
>
"11111010001110 00"
>

There are 16 hexadecimal digits, corresponding to 16 4-bit patterns. So the
idiot's way of doing it (also called "the simplest thing that could possibly
work") would be

private static readonly string[] binarySequences = new string[] {
"0000", "0001", "0010", "0011",
"0100", "0101", "0110", "0111",
"1000", "1001", "1010", "1011",
"1100", "1101", "1110", "1111",
};

static int hexDigitToInt(c har hexDigit) {
return hexDigit >= '0' && hexDigit <= '9' ? hexDigit - '0' : hexDigit
- 'A' + 10;
}
static string Hex2Bin(string hexDigits) {
StringBuilder result = new StringBuilder(h exDigits.Length * 4);
foreach (char digit in hexDigits) {
result.Append(b inarySequences[hexDigitToInt(d igit)]);
}
return result.ToString ();
}

And despite being the idiot's way, this is actually not bad. (Once you put
in validation, that is.)


--
J.

[=?UTF-8?B?QXJuZSBWYWpow7hq?=]

Re: Hexadecimal to Binary

Trecius wrote:

Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string. How can I accomplish this with minimal code? I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).
>
EXA:
>
string str = "FA38";
string binStr = SomeClass.Hex2B in(str);
>
This would produce the following output...
>
"11111010001110 00"

C# 2.0 / .NET 2.0:

public static string Hex2Bin20(strin g s)
{
StringBuilder sb = new StringBuilder() ;
foreach(char c in s.ToCharArray() )
{

sb.Append(Conve rt.ToString(Con vert.ToInt32(c. ToString(), 16),
2).PadLeft(4, '0'));
}
return sb.ToString();
}

C# 3.0 / .NET 3.5:

public static string Hex2Bin35(strin g s)
{
return String.Join("", (from c in s.ToCharArray() select
Convert.ToStrin g(Convert.ToInt 32(c.ToString() , 16), 2).PadLeft(4,
'0')).ToArray() );
}

Arne

PS: I think I would use the 2.0 version on 3.5 as well - it is
more readable.

[parez]

Re: Hexadecimal to Binary

On Jun 27, 6:56 pm, Trecius <Trec...@discus sions.microsoft .comwrote:

Hello, Newsgroupians:
>
I've a question regarding Hexadecimal to binary conversion.
>
Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string.  How can I accomplish this with minimal code?  I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).
>
EXA:
>
string str = "FA38";
string binStr = SomeClass.Hex2B in(str);
>
This would produce the following output...
>
"11111010001110 00"
>
Thank you,
>
Trecius

int i = Convert.ToInt32 ("FA38", 16);

Console.WriteLi ne(Convert.ToSt ring(i, 2));

[parez]

Re: Hexadecimal to Binary

On Jun 27, 10:18 pm, parez <psaw...@gmail. comwrote:

On Jun 27, 6:56 pm, Trecius <Trec...@discus sions.microsoft .comwrote:
>
>
>

Hello, Newsgroupians:

>

I've a question regarding Hexadecimal to binary conversion.

>

Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string.  How can I accomplish this with minimal code?  I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).

>

EXA:

>

string str = "FA38";
string binStr = SomeClass.Hex2B in(str);

>

This would produce the following output...

>

"11111010001110 00"

>

Thank you,

>

Trecius

>
            int i = Convert.ToInt32 ("FA38", 16);
>
            Console.WriteLi ne(Convert.ToSt ring(i, 2));

Sorry.. i didnt read your post all the way

[=?ISO-8859-1?Q?Arne_Vajh=F8j?=]

Re: Hexadecimal to Binary

parez wrote:

On Jun 27, 6:56 pm, Trecius <Trec...@discus sions.microsoft .comwrote:

>I've a question regarding Hexadecimal to binary conversion.
>>
>Suppose I have a long hexadecimal string, and I would like to convert it to
>a binary string. How can I accomplish this with minimal code? I've seen
>other posts, but they are restricted to the size of the hexadecimal string,
>for they use Convert.ToStrin g(...).
>>
>EXA:
>>
>string str = "FA38";
>string binStr = SomeClass.Hex2B in(str);
>>
>This would produce the following output...
>>
>"1111101000111 000"

>
int i = Convert.ToInt32 ("FA38", 16);
>
Console.WriteLi ne(Convert.ToSt ring(i, 2));

Did you read:
"I've seen other posts, but they are restricted to the size of the
hexadecimal string, for they use Convert.ToStrin g(...)"
?

Arne

[parez]

Re: Hexadecimal to Binary

On Jun 27, 10:20 pm, parez <psaw...@gmail. comwrote:

On Jun 27, 10:18 pm, parez <psaw...@gmail. comwrote:
>
>
>

On Jun 27, 6:56 pm, Trecius <Trec...@discus sions.microsoft .comwrote:

>

Hello, Newsgroupians:

>

I've a question regarding Hexadecimal to binary conversion.

>

Suppose I have a long hexadecimal string, and I would like to convertit to
a binary string.  How can I accomplish this with minimal code?  I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).

>

EXA:

>

string str = "FA38";
string binStr = SomeClass.Hex2B in(str);

>

This would produce the following output...

>

"11111010001110 00"

>

Thank you,

>

Trecius

>

            int i = Convert.ToInt32 ("FA38", 16);

>

            Console.WriteLi ne(Convert.ToSt ring(i, 2));

>
Sorry.. i didnt read your post all the way

but you could do it for each character in the string and append the
output of convert.tostrin g.

[parez]

Re: Hexadecimal to Binary

On Jun 27, 10:21 pm, Arne Vajhøj <a...@vajhoej.d kwrote:

parez wrote:

On Jun 27, 6:56 pm, Trecius <Trec...@discus sions.microsoft .comwrote:

I've a question regarding Hexadecimal to binary conversion.

>

Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string.  How can I accomplish this with minimal code?  I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).

>

EXA:

>

string str = "FA38";
string binStr = SomeClass.Hex2B in(str);

>

This would produce the following output...

>

"11111010001110 00"

>

            int i = Convert.ToInt32 ("FA38", 16);

>

            Console.WriteLi ne(Convert.ToSt ring(i, 2));

>
Did you read:
   "I've seen other posts, but they are restricted to the size of the
   hexadecimal string, for they use Convert.ToStrin g(...)"
?
>
Arne

hehe.. I didnt :)

[=?UTF-8?B?RmVybmFuZG8gR8OzbWV6?=]

Re: Hexadecimal to Binary

Trecius wrote:

Hello, Newsgroupians:
>
I've a question regarding Hexadecimal to binary conversion.
>
Suppose I have a long hexadecimal string, and I would like to convert it to
a binary string. How can I accomplish this with minimal code? I've seen
other posts, but they are restricted to the size of the hexadecimal string,
for they use Convert.ToStrin g(...).
>
EXA:
>
string str = "FA38";
string binStr = SomeClass.Hex2B in(str);
>
This would produce the following output...
>
"11111010001110 00"
>
>
Thank you,
>
>
Trecius

Hi there,

how about this? It uses int.Parse, hope that's ok.

string ToBin(string str)
{
string hex;
string bin;
int num;

bin = string.Empty;
hex = str;
num = int.Parse(hex, System.Globaliz ation.NumberSty les.HexNumber);

while (num 0)
{
bin = string.Format(" {0}{1}", (num & 1) == 1 ? "1" : "0", bin);
num >>= 1;
}

return bin;
}

I did a little test, it seems to be working fine.

Regards.

[Jeroen Mostert]

Re: Hexadecimal to Binary

Arne Vajhøj wrote:

Trecius wrote:

>Suppose I have a long hexadecimal string, and I would like to convert
>it to a binary string. How can I accomplish this with minimal code?
>I've seen other posts, but they are restricted to the size of the
>hexadecimal string, for they use Convert.ToStrin g(...).
>>
>EXA:
>>
>string str = "FA38";
>string binStr = SomeClass.Hex2B in(str);
>>
>This would produce the following output...
>>
>"1111101000111 000"

>
C# 2.0 / .NET 2.0:
>
public static string Hex2Bin20(strin g s)
{
StringBuilder sb = new StringBuilder() ;
foreach(char c in s.ToCharArray() )

This is unnecessary; System.String implements IEnumerable<cha r>.

<snip>

C# 3.0 / .NET 3.5:
>
public static string Hex2Bin35(strin g s)
{
return String.Join("", (from c in s.ToCharArray() select
Convert.ToStrin g(Convert.ToInt 32(c.ToString() , 16), 2).PadLeft(4,
'0')).ToArray() );
}
>

Without skipping on LINQ, this can easily be made more readable if desired:

public static string Hex2Bin(string hexDigits) {
return string.Concat(
(
from c in hexDigits
let hexDigit = Convert.ToInt32 (c.ToString(), 16)
let binaryDigits = Convert.ToStrin g(hexDigit, 2).PadLeft(4, '0')
select binaryDigits
).ToArray()
);
}

Or to stay in LINQ altogether:

public static string Hex2Bin(string hexDigits) {
return (
from c in hexDigits
let hexDigit = Convert.ToInt32 (c.ToString(), 16)
let binaryDigits = Convert.ToStrin g(hexDigit, 2).PadLeft(4, '0')
select binaryDigits
).Aggregate(str ing.Concat);
}

All that said, I would still prefer the "stupid" method of concatenating the
nybble strings yourself. While code like this makes the most out of reusing
existing code, I don't think it gains much on clarity, certainly not when
you throw in LINQ to impress your fellow programmers with.

--
J.

[=?UTF-8?B?QXJuZSBWYWpow7hq?=]

Re: Hexadecimal to Binary

Jeroen Mostert wrote:

Arne Vajhøj wrote:

>Trecius wrote:

>>Suppose I have a long hexadecimal string, and I would like to convert
>>it to a binary string. How can I accomplish this with minimal code?
>>I've seen other posts, but they are restricted to the size of the
>>hexadecimal string, for they use Convert.ToStrin g(...).
>>>
>>EXA:
>>>
>>string str = "FA38";
>>string binStr = SomeClass.Hex2B in(str);
>>>
>>This would produce the following output...
>>>
>>"111110100011 1000"

>>
>C# 2.0 / .NET 2.0:
>>
> public static string Hex2Bin20(strin g s)
> {
> StringBuilder sb = new StringBuilder() ;
> foreach(char c in s.ToCharArray() )

>
This is unnecessary; System.String implements IEnumerable<cha r>.

Thanks.

<snip>

>C# 3.0 / .NET 3.5:
>>
> public static string Hex2Bin35(strin g s)
> {
> return String.Join("", (from c in s.ToCharArray() select
>Convert.ToStri ng(Convert.ToIn t32(c.ToString( ), 16), 2).PadLeft(4,
>'0')).ToArray( ));
> }
>>

Without skipping on LINQ, this can easily be made more readable if desired:
>
public static string Hex2Bin(string hexDigits) {
return string.Concat(
(
from c in hexDigits
let hexDigit = Convert.ToInt32 (c.ToString(), 16)
let binaryDigits = Convert.ToStrin g(hexDigit, 2).PadLeft(4, '0')
select binaryDigits
).ToArray()
);
}
>
Or to stay in LINQ altogether:
>
public static string Hex2Bin(string hexDigits) {
return (
from c in hexDigits
let hexDigit = Convert.ToInt32 (c.ToString(), 16)
let binaryDigits = Convert.ToStrin g(hexDigit, 2).PadLeft(4, '0')
select binaryDigits
).Aggregate(str ing.Concat);
}

Many ways of doing this.

But I don't really consider those more readable.

All that said, I would still prefer the "stupid" method of concatenating
the nybble strings yourself. While code like this makes the most out of
reusing existing code, I don't think it gains much on clarity, certainly
not when you throw in LINQ to impress your fellow programmers with.

That was my conclusion as well. Bytes are pretty cheap.

Arne