How do you convert between hexadecimal numbers and decimal numbers in C#?
This question is related to
c#
hex
type-conversion
decimal
If it's a really big hex string beyond the capacity of the normal integer:
For .NET 3.5, we can use BouncyCastle's BigInteger class:
String hex = "68c7b05d0000000002f8";
// results in "494809724602834812404472"
String decimal = new Org.BouncyCastle.Math.BigInteger(hex, 16).ToString();
.NET 4.0 has the BigInteger class.
static string chex(byte e) // Convert a byte to a string representing that byte in hexadecimal
{
string r = "";
string chars = "0123456789ABCDEF";
r += chars[e >> 4];
return r += chars[e &= 0x0F];
} // Easy enough...
static byte CRAZY_BYTE(string t, int i) // Take a byte, if zero return zero, else throw exception (i=0 means false, i>0 means true)
{
if (i == 0) return 0;
throw new Exception(t);
}
static byte hbyte(string e) // Take 2 characters: these are hex chars, convert it to a byte
{ // WARNING: This code will make small children cry. Rated R.
e = e.ToUpper(); //
string msg = "INVALID CHARS"; // The message that will be thrown if the hex str is invalid
byte[] t = new byte[] // Gets the 2 characters and puts them in seperate entries in a byte array.
{ // This will throw an exception if (e.Length != 2).
(byte)e[CRAZY_BYTE("INVALID LENGTH", e.Length ^ 0x02)],
(byte)e[0x01]
};
for (byte i = 0x00; i < 0x02; i++) // Convert those [ascii] characters to [hexadecimal] characters. Error out if either character is invalid.
{
t[i] -= (byte)((t[i] >= 0x30) ? 0x30 : CRAZY_BYTE(msg, 0x01)); // Check for 0-9
t[i] -= (byte)((!(t[i] < 0x0A)) ? (t[i] >= 0x11 ? 0x07 : CRAZY_BYTE(msg, 0x01)) : 0x00); // Check for A-F
}
return t[0x01] |= t[0x00] <<= 0x04; // The moment of truth.
}
This is not really easiest way but this source code enable you to right any types of octal number i.e 23.214, 23 and 0.512 and so on. Hope this will help you..
public string octal_to_decimal(string m_value)
{
double i, j, x = 0;
Int64 main_value;
int k = 0;
bool pw = true, ch;
int position_pt = m_value.IndexOf(".");
if (position_pt == -1)
{
main_value = Convert.ToInt64(m_value);
ch = false;
}
else
{
main_value = Convert.ToInt64(m_value.Remove(position_pt, m_value.Length - position_pt));
ch = true;
}
while (k <= 1)
{
do
{
i = main_value % 10; // Return Remainder
i = i * Convert.ToDouble(Math.Pow(8, x)); // calculate power
if (pw)
x++;
else
x--;
o_to_d = o_to_d + i; // Saving Required calculated value in main variable
main_value = main_value / 10; // Dividing the main value
}
while (main_value >= 1);
if (ch)
{
k++;
main_value = Convert.ToInt64(Reversestring(m_value.Remove(0, position_pt + 1)));
}
else
k = 2;
pw = false;
x = -1;
}
return (Convert.ToString(o_to_d));
}
It looks like you can say
Convert.ToInt64(value, 16)
to get the decimal from hexdecimal.
The other way around is:
otherVar.ToString("X");
String stringrep = myintvar.ToString("X");
int num = int.Parse("FF", System.Globalization.NumberStyles.HexNumber);
An extension method for converting a byte array into a hex representation. This pads each byte with leading zeros.
/// <summary>
/// Turns the byte array into its Hex representation.
/// </summary>
public static string ToHex(this byte[] y)
{
StringBuilder sb = new StringBuilder();
foreach (byte b in y)
{
sb.Append(b.ToString("X").PadLeft(2, "0"[0]));
}
return sb.ToString();
}
String stringrep = myintvar.ToString("X");
int num = int.Parse("FF", System.Globalization.NumberStyles.HexNumber);
String stringrep = myintvar.ToString("X");
int num = int.Parse("FF", System.Globalization.NumberStyles.HexNumber);
Hex to Decimal Conversion
Convert.ToInt32(number, 16);
Decimal to Hex Conversion
int.Parse(number, System.Globalization.NumberStyles.HexNumber)
It looks like you can say
Convert.ToInt64(value, 16)
to get the decimal from hexdecimal.
The other way around is:
otherVar.ToString("X");
My solution is a bit like back to basics, but it works without using any built-in functions to convert between number systems.
public static string DecToHex(long a)
{
int n = 1;
long b = a;
while (b > 15)
{
b /= 16;
n++;
}
string[] t = new string[n];
int i = 0, j = n - 1;
do
{
if (a % 16 == 10) t[i] = "A";
else if (a % 16 == 11) t[i] = "B";
else if (a % 16 == 12) t[i] = "C";
else if (a % 16 == 13) t[i] = "D";
else if (a % 16 == 14) t[i] = "E";
else if (a % 16 == 15) t[i] = "F";
else t[i] = (a % 16).ToString();
a /= 16;
i++;
}
while ((a * 16) > 15);
string[] r = new string[n];
for (i = 0; i < n; i++)
{
r[i] = t[j];
j--;
}
string res = string.Concat(r);
return res;
}
It looks like you can say
Convert.ToInt64(value, 16)
to get the decimal from hexdecimal.
The other way around is:
otherVar.ToString("X");
class HexToDecimal
{
static void Main()
{
while (true)
{
Console.Write("Enter digit number to convert: ");
int n = int.Parse(Console.ReadLine()); // set hexadecimal digit number
Console.Write("Enter hexadecimal number: ");
string str = Console.ReadLine();
str.Reverse();
char[] ch = str.ToCharArray();
int[] intarray = new int[n];
decimal decimalval = 0;
for (int i = ch.Length - 1; i >= 0; i--)
{
if (ch[i] == '0')
intarray[i] = 0;
if (ch[i] == '1')
intarray[i] = 1;
if (ch[i] == '2')
intarray[i] = 2;
if (ch[i] == '3')
intarray[i] = 3;
if (ch[i] == '4')
intarray[i] = 4;
if (ch[i] == '5')
intarray[i] = 5;
if (ch[i] == '6')
intarray[i] = 6;
if (ch[i] == '7')
intarray[i] = 7;
if (ch[i] == '8')
intarray[i] = 8;
if (ch[i] == '9')
intarray[i] = 9;
if (ch[i] == 'A')
intarray[i] = 10;
if (ch[i] == 'B')
intarray[i] = 11;
if (ch[i] == 'C')
intarray[i] = 12;
if (ch[i] == 'D')
intarray[i] = 13;
if (ch[i] == 'E')
intarray[i] = 14;
if (ch[i] == 'F')
intarray[i] = 15;
decimalval += intarray[i] * (decimal)Math.Pow(16, ch.Length - 1 - i);
}
Console.WriteLine(decimalval);
}
}
}
My version is I think a little more understandable because my C# knowledge is not so high. I'm using this algorithm: http://easyguyevo.hubpages.com/hub/Convert-Hex-to-Decimal (The Example 2)
using System;
using System.Collections.Generic;
static class Tool
{
public static string DecToHex(int x)
{
string result = "";
while (x != 0)
{
if ((x % 16) < 10)
result = x % 16 + result;
else
{
string temp = "";
switch (x % 16)
{
case 10: temp = "A"; break;
case 11: temp = "B"; break;
case 12: temp = "C"; break;
case 13: temp = "D"; break;
case 14: temp = "E"; break;
case 15: temp = "F"; break;
}
result = temp + result;
}
x /= 16;
}
return result;
}
public static int HexToDec(string x)
{
int result = 0;
int count = x.Length - 1;
for (int i = 0; i < x.Length; i++)
{
int temp = 0;
switch (x[i])
{
case 'A': temp = 10; break;
case 'B': temp = 11; break;
case 'C': temp = 12; break;
case 'D': temp = 13; break;
case 'E': temp = 14; break;
case 'F': temp = 15; break;
default: temp = -48 + (int)x[i]; break; // -48 because of ASCII
}
result += temp * (int)(Math.Pow(16, count));
count--;
}
return result;
}
}
class Program
{
static void Main(string[] args)
{
Console.Write("Enter Decimal value: ");
int decNum = int.Parse(Console.ReadLine());
Console.WriteLine("Dec {0} is hex {1}", decNum, Tool.DecToHex(decNum));
Console.Write("\nEnter Hexadecimal value: ");
string hexNum = Console.ReadLine().ToUpper();
Console.WriteLine("Hex {0} is dec {1}", hexNum, Tool.HexToDec(hexNum));
Console.ReadKey();
}
}
My solution is a bit like back to basics, but it works without using any built-in functions to convert between number systems.
public static string DecToHex(long a)
{
int n = 1;
long b = a;
while (b > 15)
{
b /= 16;
n++;
}
string[] t = new string[n];
int i = 0, j = n - 1;
do
{
if (a % 16 == 10) t[i] = "A";
else if (a % 16 == 11) t[i] = "B";
else if (a % 16 == 12) t[i] = "C";
else if (a % 16 == 13) t[i] = "D";
else if (a % 16 == 14) t[i] = "E";
else if (a % 16 == 15) t[i] = "F";
else t[i] = (a % 16).ToString();
a /= 16;
i++;
}
while ((a * 16) > 15);
string[] r = new string[n];
for (i = 0; i < n; i++)
{
r[i] = t[j];
j--;
}
string res = string.Concat(r);
return res;
}
Convert binary to Hex
Convert.ToString(Convert.ToUInt32(binary1, 2), 16).ToUpper()
Hex -> decimal:
Convert.ToInt64(hexValue, 16);
Decimal -> Hex
string.format("{0:x}", decValue);
// Store integer 182
int decValue = 182;
// Convert integer 182 as a hex in a string variable
string hexValue = decValue.ToString("X");
// Convert the hex string back to the number
int decAgain = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);
class HexToDecimal
{
static void Main()
{
while (true)
{
Console.Write("Enter digit number to convert: ");
int n = int.Parse(Console.ReadLine()); // set hexadecimal digit number
Console.Write("Enter hexadecimal number: ");
string str = Console.ReadLine();
str.Reverse();
char[] ch = str.ToCharArray();
int[] intarray = new int[n];
decimal decimalval = 0;
for (int i = ch.Length - 1; i >= 0; i--)
{
if (ch[i] == '0')
intarray[i] = 0;
if (ch[i] == '1')
intarray[i] = 1;
if (ch[i] == '2')
intarray[i] = 2;
if (ch[i] == '3')
intarray[i] = 3;
if (ch[i] == '4')
intarray[i] = 4;
if (ch[i] == '5')
intarray[i] = 5;
if (ch[i] == '6')
intarray[i] = 6;
if (ch[i] == '7')
intarray[i] = 7;
if (ch[i] == '8')
intarray[i] = 8;
if (ch[i] == '9')
intarray[i] = 9;
if (ch[i] == 'A')
intarray[i] = 10;
if (ch[i] == 'B')
intarray[i] = 11;
if (ch[i] == 'C')
intarray[i] = 12;
if (ch[i] == 'D')
intarray[i] = 13;
if (ch[i] == 'E')
intarray[i] = 14;
if (ch[i] == 'F')
intarray[i] = 15;
decimalval += intarray[i] * (decimal)Math.Pow(16, ch.Length - 1 - i);
}
Console.WriteLine(decimalval);
}
}
}
If you want maximum performance when doing conversion from hex to decimal number, you can use the approach with pre-populated table of hex-to-decimal values.
Here is the code that illustrates that idea. My performance tests showed that it can be 20%-40% faster than Convert.ToInt32(...):
class TableConvert
{
static sbyte[] unhex_table =
{ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1
,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
};
public static int Convert(string hexNumber)
{
int decValue = unhex_table[(byte)hexNumber[0]];
for (int i = 1; i < hexNumber.Length; i++)
{
decValue *= 16;
decValue += unhex_table[(byte)hexNumber[i]];
}
return decValue;
}
}
This is not really easiest way but this source code enable you to right any types of octal number i.e 23.214, 23 and 0.512 and so on. Hope this will help you..
public string octal_to_decimal(string m_value)
{
double i, j, x = 0;
Int64 main_value;
int k = 0;
bool pw = true, ch;
int position_pt = m_value.IndexOf(".");
if (position_pt == -1)
{
main_value = Convert.ToInt64(m_value);
ch = false;
}
else
{
main_value = Convert.ToInt64(m_value.Remove(position_pt, m_value.Length - position_pt));
ch = true;
}
while (k <= 1)
{
do
{
i = main_value % 10; // Return Remainder
i = i * Convert.ToDouble(Math.Pow(8, x)); // calculate power
if (pw)
x++;
else
x--;
o_to_d = o_to_d + i; // Saving Required calculated value in main variable
main_value = main_value / 10; // Dividing the main value
}
while (main_value >= 1);
if (ch)
{
k++;
main_value = Convert.ToInt64(Reversestring(m_value.Remove(0, position_pt + 1)));
}
else
k = 2;
pw = false;
x = -1;
}
return (Convert.ToString(o_to_d));
}
// Store integer 182
int decValue = 182;
// Convert integer 182 as a hex in a string variable
string hexValue = decValue.ToString("X");
// Convert the hex string back to the number
int decAgain = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);
Try using BigNumber in C# - Represents an arbitrarily large signed integer.
using System.Numerics;
...
var bigNumber = BigInteger.Parse("837593454735734579347547357233757342857087879423437472347757234945743");
Console.WriteLine(bigNumber.ToString("X"));
4F30DC39A5B10A824134D5B18EEA3707AC854EE565414ED2E498DCFDE1A15DA5FEB6074AE248458435BD417F06F674EB29A2CFECF
ArgumentNullException - value is null.
FormatException - value is not in the correct format.
You can convert string and store a value in BigNumber without constraints about the size of the number unless the string is empty and non-analphabets
Hex -> decimal:
Convert.ToInt64(hexValue, 16);
Decimal -> Hex
string.format("{0:x}", decValue);
An extension method for converting a byte array into a hex representation. This pads each byte with leading zeros.
/// <summary>
/// Turns the byte array into its Hex representation.
/// </summary>
public static string ToHex(this byte[] y)
{
StringBuilder sb = new StringBuilder();
foreach (byte b in y)
{
sb.Append(b.ToString("X").PadLeft(2, "0"[0]));
}
return sb.ToString();
}
// Store integer 182
int decValue = 182;
// Convert integer 182 as a hex in a string variable
string hexValue = decValue.ToString("X");
// Convert the hex string back to the number
int decAgain = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);
Hex to Decimal Conversion
Convert.ToInt32(number, 16);
Decimal to Hex Conversion
int.Parse(number, System.Globalization.NumberStyles.HexNumber)
If it's a really big hex string beyond the capacity of the normal integer:
For .NET 3.5, we can use BouncyCastle's BigInteger class:
String hex = "68c7b05d0000000002f8";
// results in "494809724602834812404472"
String decimal = new Org.BouncyCastle.Math.BigInteger(hex, 16).ToString();
.NET 4.0 has the BigInteger class.
// Store integer 182
int decValue = 182;
// Convert integer 182 as a hex in a string variable
string hexValue = decValue.ToString("X");
// Convert the hex string back to the number
int decAgain = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);
static string chex(byte e) // Convert a byte to a string representing that byte in hexadecimal
{
string r = "";
string chars = "0123456789ABCDEF";
r += chars[e >> 4];
return r += chars[e &= 0x0F];
} // Easy enough...
static byte CRAZY_BYTE(string t, int i) // Take a byte, if zero return zero, else throw exception (i=0 means false, i>0 means true)
{
if (i == 0) return 0;
throw new Exception(t);
}
static byte hbyte(string e) // Take 2 characters: these are hex chars, convert it to a byte
{ // WARNING: This code will make small children cry. Rated R.
e = e.ToUpper(); //
string msg = "INVALID CHARS"; // The message that will be thrown if the hex str is invalid
byte[] t = new byte[] // Gets the 2 characters and puts them in seperate entries in a byte array.
{ // This will throw an exception if (e.Length != 2).
(byte)e[CRAZY_BYTE("INVALID LENGTH", e.Length ^ 0x02)],
(byte)e[0x01]
};
for (byte i = 0x00; i < 0x02; i++) // Convert those [ascii] characters to [hexadecimal] characters. Error out if either character is invalid.
{
t[i] -= (byte)((t[i] >= 0x30) ? 0x30 : CRAZY_BYTE(msg, 0x01)); // Check for 0-9
t[i] -= (byte)((!(t[i] < 0x0A)) ? (t[i] >= 0x11 ? 0x07 : CRAZY_BYTE(msg, 0x01)) : 0x00); // Check for A-F
}
return t[0x01] |= t[0x00] <<= 0x04; // The moment of truth.
}
Convert binary to Hex
Convert.ToString(Convert.ToUInt32(binary1, 2), 16).ToUpper()
If you want maximum performance when doing conversion from hex to decimal number, you can use the approach with pre-populated table of hex-to-decimal values.
Here is the code that illustrates that idea. My performance tests showed that it can be 20%-40% faster than Convert.ToInt32(...):
class TableConvert
{
static sbyte[] unhex_table =
{ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1
,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
};
public static int Convert(string hexNumber)
{
int decValue = unhex_table[(byte)hexNumber[0]];
for (int i = 1; i < hexNumber.Length; i++)
{
decValue *= 16;
decValue += unhex_table[(byte)hexNumber[i]];
}
return decValue;
}
}
Hex -> decimal:
Convert.ToInt64(hexValue, 16);
Decimal -> Hex
string.format("{0:x}", decValue);
My version is I think a little more understandable because my C# knowledge is not so high. I'm using this algorithm: http://easyguyevo.hubpages.com/hub/Convert-Hex-to-Decimal (The Example 2)
using System;
using System.Collections.Generic;
static class Tool
{
public static string DecToHex(int x)
{
string result = "";
while (x != 0)
{
if ((x % 16) < 10)
result = x % 16 + result;
else
{
string temp = "";
switch (x % 16)
{
case 10: temp = "A"; break;
case 11: temp = "B"; break;
case 12: temp = "C"; break;
case 13: temp = "D"; break;
case 14: temp = "E"; break;
case 15: temp = "F"; break;
}
result = temp + result;
}
x /= 16;
}
return result;
}
public static int HexToDec(string x)
{
int result = 0;
int count = x.Length - 1;
for (int i = 0; i < x.Length; i++)
{
int temp = 0;
switch (x[i])
{
case 'A': temp = 10; break;
case 'B': temp = 11; break;
case 'C': temp = 12; break;
case 'D': temp = 13; break;
case 'E': temp = 14; break;
case 'F': temp = 15; break;
default: temp = -48 + (int)x[i]; break; // -48 because of ASCII
}
result += temp * (int)(Math.Pow(16, count));
count--;
}
return result;
}
}
class Program
{
static void Main(string[] args)
{
Console.Write("Enter Decimal value: ");
int decNum = int.Parse(Console.ReadLine());
Console.WriteLine("Dec {0} is hex {1}", decNum, Tool.DecToHex(decNum));
Console.Write("\nEnter Hexadecimal value: ");
string hexNum = Console.ReadLine().ToUpper();
Console.WriteLine("Hex {0} is dec {1}", hexNum, Tool.HexToDec(hexNum));
Console.ReadKey();
}
}
Hex -> decimal:
Convert.ToInt64(hexValue, 16);
Decimal -> Hex
string.format("{0:x}", decValue);
It looks like you can say
Convert.ToInt64(value, 16)
to get the decimal from hexdecimal.
The other way around is:
otherVar.ToString("X");
Here is my function:
using System;
using System.Collections.Generic;
class HexadecimalToDecimal
{
static Dictionary<char, int> hexdecval = new Dictionary<char, int>{
{'0', 0},
{'1', 1},
{'2', 2},
{'3', 3},
{'4', 4},
{'5', 5},
{'6', 6},
{'7', 7},
{'8', 8},
{'9', 9},
{'a', 10},
{'b', 11},
{'c', 12},
{'d', 13},
{'e', 14},
{'f', 15},
};
static decimal HexToDec(string hex)
{
decimal result = 0;
hex = hex.ToLower();
for (int i = 0; i < hex.Length; i++)
{
char valAt = hex[hex.Length - 1 - i];
result += hexdecval[valAt] * (int)Math.Pow(16, i);
}
return result;
}
static void Main()
{
Console.WriteLine("Enter Hexadecimal value");
string hex = Console.ReadLine().Trim();
//string hex = "29A";
Console.WriteLine("Hex {0} is dec {1}", hex, HexToDec(hex));
Console.ReadKey();
}
}
Try using BigNumber in C# - Represents an arbitrarily large signed integer.
using System.Numerics;
...
var bigNumber = BigInteger.Parse("837593454735734579347547357233757342857087879423437472347757234945743");
Console.WriteLine(bigNumber.ToString("X"));
4F30DC39A5B10A824134D5B18EEA3707AC854EE565414ED2E498DCFDE1A15DA5FEB6074AE248458435BD417F06F674EB29A2CFECF
ArgumentNullException - value is null.
FormatException - value is not in the correct format.
You can convert string and store a value in BigNumber without constraints about the size of the number unless the string is empty and non-analphabets
Here is my function:
using System;
using System.Collections.Generic;
class HexadecimalToDecimal
{
static Dictionary<char, int> hexdecval = new Dictionary<char, int>{
{'0', 0},
{'1', 1},
{'2', 2},
{'3', 3},
{'4', 4},
{'5', 5},
{'6', 6},
{'7', 7},
{'8', 8},
{'9', 9},
{'a', 10},
{'b', 11},
{'c', 12},
{'d', 13},
{'e', 14},
{'f', 15},
};
static decimal HexToDec(string hex)
{
decimal result = 0;
hex = hex.ToLower();
for (int i = 0; i < hex.Length; i++)
{
char valAt = hex[hex.Length - 1 - i];
result += hexdecval[valAt] * (int)Math.Pow(16, i);
}
return result;
}
static void Main()
{
Console.WriteLine("Enter Hexadecimal value");
string hex = Console.ReadLine().Trim();
//string hex = "29A";
Console.WriteLine("Hex {0} is dec {1}", hex, HexToDec(hex));
Console.ReadKey();
}
}
Source: Stackoverflow.com