Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
Solved

How to convert a 39-decimal characters into hex in c#

Posted on 2013-11-06
Medium Priority
1,058 Views
Hi experts
I've a string representation of a 39-characters long decimal integer.
I need to convert this into hex format in C#.
eg. 340282366920938463463374607431768211455 (39 characters)
-> ffffffffffffffffffffffffffffffff (32 characters)

By the same token, I need to be able to reverse the operation from hex to decimal.

I am using C# .NET 3.5 which hasn't got BigInteger.

0
Question by:dominicwong
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

• Help others & share knowledge
• Earn cash & points
• 2

LVL 9

Accepted Solution

QuinnDex earned 2000 total points
ID: 39629440
the code for doing this in strings is below but if you want to work in numbers try intX

https://github.com/devoyster/IntXLib

decimal string to hex string

``````        var s = "843370923007003347112437570992242323";
var result = new List<byte>();
foreach ( char c in s )
{
int val = (int)( c - '0' );
for ( int i = 0 ; i < result.Count ; i++ )
{
int digit = result[i] * 10 + val;
result[i] = (byte)( digit & 0x0F );
val = digit >> 4;
}
if ( val != 0 )
}

var hex = "";
foreach ( byte b in result )
hex = "0123456789ABCDEF"[ b ] + hex;
``````

hex string to decimal string

``````static string HexToDecimal(string hex)
{
List<int> dec = new List<int> { 0 };   // decimal result

foreach (char c in hex)
{
int carry = Convert.ToInt32(c.ToString(), 16);
// initially holds decimal value of current hex digit;
// subsequently holds carry-over for multiplication

for (int i = 0; i < dec.Count; ++i)
{
int val = dec[i] * 16 + carry;
dec[i] = val % 10;
carry = val / 10;
}

while (carry > 0)
{
carry /= 10;
}
}

var chars = dec.Select(d => (char)('0' + d));
var cArr = chars.Reverse().ToArray();
return new string(cArr);
}
``````
0

LVL 40

Expert Comment

ID: 39629453
There is a BigInteger. It is "hidden" in the System.Numerics namespace, available after referencing the dll by the same name.

If you can get a string representation of your value, the following will do the job:

BigInteger bigInt = BigInteger.Parse ( "340282366920938463463374607431768211455" );
string bigHex = bigInt.ToString ("X");
bigInt = BigInteger.Parse ( bigHex, System.Globalization.NumberStyles.HexNumber );

Otherwise, give a look at the BigInteger Structure in the documentation, it is quite exhaustive.
0

LVL 9

Expert Comment

ID: 39629466
BigInteger is part of .net 4, OP is working with .net 3.5
0

Author Closing Comment

ID: 39629467
Thanks QuinnDex. That works like a charm, and is exactly what I need.

Thanks also to JamesBurger for your help.
0

Featured Post

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This document covers how to connect to SQL Server and browse its contents.  It is meant for those new to Visual Studio and/or working with Microsoft SQL Server.  It is not a guide to building SQL Server database connections in your code.  This is mo…
The article shows the basic steps of integrating an HTML theme template into an ASP.NET MVC project
In this video you will find out how to export Office 365 mailboxes using the built in eDiscovery tool. Bear in mind that although this method might be useful in some cases, using PST files as Office 365 backup is troublesome in a long run (more on t…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
Suggested Courses
Course of the Month12 days, left to enroll