Byte Structure

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Represents an 8-bit unsigned integer.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
<ComVisibleAttribute(True)> _
Public Structure Byte _
    Implements IComparable, IFormattable, IConvertible, IComparable(Of Byte),  _
    IEquatable(Of Byte)

[ComVisibleAttribute(true)]
public struct Byte : IComparable, IFormattable, 
    IConvertible, IComparable<byte>, IEquatable<byte>

The Byte type exposes the following members.

Methods

	Name	Description
	CompareTo(Byte)	Compares this instance to a specified 8-bit unsigned integer and returns an indication of their relative values.
	CompareTo(Object)	Compares this instance to a specified object and returns an indication of their relative values.
	Equals(Byte)	Returns a value indicating whether this instance and a specified Byte object represent the same value.
	Equals(Object)	Returns a value indicating whether this instance is equal to a specified object. (Overrides ValueType.Equals(Object).)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Returns the hash code for this instance. (Overrides ValueType.GetHashCode().)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetTypeCode	Returns the TypeCode for value type Byte.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	Parse(String)	Converts the string representation of a number to its Byte equivalent.
	Parse(String, NumberStyles)	Converts the string representation of a number in a specified style to its Byte equivalent.
	Parse(String, IFormatProvider)	Converts the string representation of a number in a specified culture-specific format to its Byte equivalent.
	Parse(String, NumberStyles, IFormatProvider)	Converts the string representation of a number in a specified style and culture-specific format to its Byte equivalent.
	ToString()	Converts the value of the current Byte object to its equivalent string representation. (Overrides ValueType.ToString().)
	ToString(IFormatProvider)	Converts the numeric value of the current Byte object to its equivalent string representation using the specified culture-specific formatting information.
	ToString(String)	Converts the value of the current Byte object to its equivalent string representation using the specified format.
	ToString(String, IFormatProvider)	Converts the value of the current Byte object to its equivalent string representation using the specified format and culture-specific formatting information.
	TryParse(String, Byte%)	Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.
	TryParse(String, NumberStyles, IFormatProvider, Byte%)	Converts the string representation of a number in a specified style and culture-specific format to its Byte equivalent. A return value indicates whether the conversion succeeded or failed.

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Fields

	Name	Description
	MaxValue	Represents the largest possible value of a Byte. This field is constant.
	MinValue	Represents the smallest possible value of a Byte. This field is constant.

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Explicit Interface Implementations

	Name	Description
	IConvertible.ToBoolean	Infrastructure. For a description of this member, see IConvertible.ToBoolean.
	IConvertible.ToByte	Infrastructure. For a description of this member, see IConvertible.ToByte.
	IConvertible.ToChar	Infrastructure. For a description of this member, see IConvertible.ToChar.
	IConvertible.ToDateTime	Infrastructure. This conversion is not supported. Attempting to use this method throws an InvalidCastException.
	IConvertible.ToDecimal	Infrastructure. For a description of this member, see IConvertible.ToDecimal.
	IConvertible.ToDouble	Infrastructure. For a description of this member, see IConvertible.ToDouble.
	IConvertible.ToInt16	Infrastructure. For a description of this member, see IConvertible.ToInt16.
	IConvertible.ToInt32	Infrastructure. For a description of this member, see IConvertible.ToInt32.
	IConvertible.ToInt64	Infrastructure. For a description of this member, see IConvertible.ToInt64.
	IConvertible.ToSByte	Infrastructure. For a description of this member, see IConvertible.ToSByte.
	IConvertible.ToSingle	Infrastructure. For a description of this member, see IConvertible.ToSingle.
	IConvertible.ToType	Infrastructure. For a description of this member, see IConvertible.ToType.
	IConvertible.ToUInt16	Infrastructure. For a description of this member, see IConvertible.ToUInt16.
	IConvertible.ToUInt32	Infrastructure. For a description of this member, see IConvertible.ToUInt32.
	IConvertible.ToUInt64	Infrastructure. For a description of this member, see IConvertible.ToUInt64.

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Remarks

Byte is an immutable value type that represents unsigned integers with values that range from 0 (which is represented by the Byte.MinValue constant) to 255 (which is represented by the Byte.MaxValue constant). The .NET Framework also includes a signed 8-bit integer value type, SByte, which represents values that range from -128 to 127.

Instantiating a Byte Value

You can instantiate a Byte value in several ways:

• You can declare a Byte variable and assign it a literal integer value that is within the range of the Byte data type. The following example declares two Byte variables and assigns them values in this way.

  Dim value1 As Byte = 64
  Dim value2 As Byte = 255
  

  byte value1 = 64;
  byte value2 = 255;
  

• You can assign a non-byte numeric value to a byte. This is a narrowing conversion, so it requires a cast operator in C# and a conversion method in Visual Basic if OptionStrict is on. If the non-byte value is a Single, Double, or Decimal value that includes a fractional component, its fractional part is truncated. The following example assigns several numeric values to Byte variables.

  Dim int1 As Integer = 128
  Try
     Dim value1 As Byte = CByte(int1)
     outputBlock.Text &= value1 & vbCrLf
  Catch e As OverflowException
     outputBlock.Text += String.Format("{0} is out of range of a byte.", int1) & vbCrLf
  End Try
  
  Dim dbl2 As Double = 3.997
  Try
     Dim value2 As Byte = CByte(dbl2)
     outputBlock.Text &= value2 & vbCrLf
  Catch e As OverflowException
     outputBlock.Text += String.Format("{0} is out of range of a byte.", dbl2) & vbCrLf
  End Try
  ' The example displays the following output:
  '       128
  '       4
  

  int int1 = 128;
  try
  {
     byte value1 = (byte)int1;
     outputBlock.Text += value1 + Environment.NewLine;
  }
  catch (OverflowException)
  {
     outputBlock.Text += String.Format("{0} is out of range of a byte.", int1) + "\n";
  }
  
  double dbl2 = 3.997;
  try
  {
     byte value2 = (byte)dbl2;
     outputBlock.Text += value2 + "\n";
  }
  catch (OverflowException)
  {
     outputBlock.Text += String.Format("{0} is out of range of a byte.", dbl2) + "\n";
  }
  // The example displays the following output:
  //       128
  //       3      
  

• You can call a method of the Convert class to convert any supported type to a Byte value. This is possible because Byte supports the IConvertible interface. The following example illustrates the conversion of an array of Int32 values to Byte values.

  Dim numbers() As Integer = {Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue}
  Dim result As Byte
  For Each number As Integer In numbers
     Try
        result = Convert.ToByte(number)
        outputBlock.Text += String.Format("Converted the {0} value {1} to the {2} value {3}.", _
                          number.GetType().Name, number, _
                          result.GetType().Name, result) & vbCrLf
     Catch e As OverflowException
        outputBlock.Text += String.Format("The {0} value {1} is outside the range of the Byte type.", _
                          number.GetType().Name, number) & vbCrLf
     End Try
  Next
  ' The example displays the following output:
  '       The Int32 value -2147483648 is outside the range of the Byte type.
  '       The Int32 value -1 is outside the range of the Byte type.
  '       Converted the Int32 value 0 to the Byte value 0.
  '       Converted the Int32 value 121 to the Byte value 121.
  '       The Int32 value 340 is outside the range of the Byte type.
  '       The Int32 value 2147483647 is outside the range of the Byte type.      
  

  int[] numbers = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue };
  byte result;
  foreach (int number in numbers)
  {
     try
     {
        result = Convert.ToByte(number);
        outputBlock.Text += String.Format("Converted the {0} value {1} to the {2} value {3}.",
                          number.GetType().Name, number,
                          result.GetType().Name, result) + "\n";
     }
     catch (OverflowException)
     {
        outputBlock.Text += String.Format("The {0} value {1} is outside the range of the Byte type.",
                          number.GetType().Name, number) + "\n";
     }
  }
  // The example displays the following output:
  //       The Int32 value -2147483648 is outside the range of the Byte type.
  //       The Int32 value -1 is outside the range of the Byte type.
  //       Converted the Int32 value 0 to the Byte value 0.
  //       Converted the Int32 value 121 to the Byte value 121.
  //       The Int32 value 340 is outside the range of the Byte type.
  //       The Int32 value 2147483647 is outside the range of the Byte type.      
  

• You can call the Parse or TryParse method to convert the string representation of a Byte value to a Byte. The string can contain either decimal or hexadecimal digits. The following example illustrates the parse operation by using both a decimal and a hexadecimal string.

  Dim string1 As String = "244"
  Try
     Dim byte1 As Byte = Byte.Parse(string1)
     outputBlock.Text &= byte1 & vbCrLf
  Catch e As OverflowException
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string1) & vbCrLf
  Catch e As FormatException
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string1) & vbCrLf
  End Try
  
  Dim string2 As String = "F9"
  Try
     Dim byte2 As Byte = Byte.Parse(string2,
                               System.Globalization.NumberStyles.HexNumber)
     outputBlock.Text &= byte2 & vbCrLf
  Catch e As OverflowException
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string2) & vbCrLf
  Catch e As FormatException
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string2) & vbCrLf
  End Try
  ' The example displays the following output:
  '       244
  '       249
  

  string string1 = "244";
  try
  {
     byte byte1 = Byte.Parse(string1);
     outputBlock.Text += byte1 + "\n";
  }
  catch (OverflowException)
  {
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string1) + "\n";
  }
  catch (FormatException)
  {
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string1) + "\n";
  }
  
  string string2 = "F9";
  try
  {
     byte byte2 = Byte.Parse(string2,
                             System.Globalization.NumberStyles.HexNumber);
     outputBlock.Text += byte2 + "\n";
  }
  catch (OverflowException)
  {
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string2) + "\n";
  }
  catch (FormatException)
  {
     outputBlock.Text += String.Format("'{0}' is out of range of a byte.", string2) + "\n";
  }
  // The example displays the following output:
  //       244
  //       249
  

Performing Operations on Byte Values

The Byte type supports standard mathematical operations such as addition, subtraction, division, multiplication, subtraction, negation, and unary negation. Like the other integral types, the Byte type also supports the bitwise AND, OR, XOR, left shift, and right shift operators.

You can use the standard numeric operators to compare two Byte values, or you can call the CompareTo or Equals method.

Representing a Byte as a String

The Byte type provides full support for standard and custom numeric format strings. (For more information, see Formatting Types, Standard Numeric Format Strings, and Custom Numeric Format Strings.) However, most commonly, byte values are represented as one-digit to three-digit values without any additional formatting, or as two-digit hexadecimal values.

To format a Byte value as an integral string with no leading zeros, you can call the parameterless ToString() method. By using the "D" format specifier, you can also include a specified number of leading zeros in the string representation. By using the "X" format specifier, you can represent a Byte value as a hexadecimal string. The following example formats the elements in an array of Byte values in these three ways.

outputBlock.FontFamily = New System.Windows.Media.FontFamily("Courier New")

Dim numbers() As Byte = {0, 16, 104, 213}
For Each number As Byte In numbers
   ' Display value using default formatting.
   outputBlock.Text += String.Format("{0,-3}  -->   ", number.ToString())
   ' Display value with 3 digits and leading zeros.
   outputBlock.Text &= number.ToString("D3") + "   "
   ' Display value with hexadecimal.
   outputBlock.Text &= number.ToString("X2") + "   "
   ' Display value with four hexadecimal digits.
   outputBlock.Text &= number.ToString("X4") & vbCrLf
Next
' The example displays the following output:
'       0    -->   000   00   0000
'       16   -->   016   10   0010
'       104  -->   104   68   0068
'       213  -->   213   D5   00D5      

outputBlock.FontFamily = new System.Windows.Media.FontFamily("Courier New");

byte[] numbers = { 0, 16, 104, 213 };
foreach (byte number in numbers)
{
   // Display value using default formatting.
   outputBlock.Text += String.Format("{0,-3}  -->   ", number.ToString());
   // Display value with 3 digits and leading zeros.
   outputBlock.Text += number.ToString("D3") + "   ";
   // Display value with hexadecimal.
   outputBlock.Text += number.ToString("X2") + "   ";
   // Display value with four hexadecimal digits.
   outputBlock.Text += number.ToString("X4") + "\n";
}
// The example displays the following output:
//       0    -->   000   00   0000
//       16   -->   016   10   0010
//       104  -->   104   68   0068
//       213  -->   213   D5   00D5      

You can also format a Byte value as a binary, octal, decimal, or hexadecimal string by calling the ToString(Byte, Int32) method and supplying the base as the method's second parameter. The following example calls this method to display the binary, octal, and hexadecimal representations of an array of byte values.

Dim numbers() As Byte = {0, 16, 104, 213}
outputBlock.Text += String.Format("{0}   {1,8}   {2,5}   {3,5}", _
                  "Value", "Binary", "Octal", "Hex") & vbCrLf
For Each number As Byte In numbers
   outputBlock.Text += String.Format("{0,5}   {1,8}   {2,5}   {3,5}", _
                     number, Convert.ToString(number, 2), _
                     Convert.ToString(number, 8), _
                     Convert.ToString(number, 16)) & vbCrLf
Next
' The example displays the following output:
'       Value     Binary   Octal     Hex
'           0          0       0       0
'          16      10000      20      10
'         104    1101000     150      68
'         213   11010101     325      d5      

byte[] numbers = { 0, 16, 104, 213 };
outputBlock.Text += String.Format("{0}   {1,8}   {2,5}   {3,5}",
                  "Value", "Binary", "Octal", "Hex") + "\n";
foreach (byte number in numbers)
{
   outputBlock.Text += String.Format("{0,5}   {1,8}   {2,5}   {3,5}",
                     number, Convert.ToString(number, 2),
                     Convert.ToString(number, 8),
                     Convert.ToString(number, 16)) + "\n";
}
// The example displays the following output:
//       Value     Binary   Octal     Hex
//           0          0       0       0
//          16      10000      20      10
//         104    1101000     150      68
//         213   11010101     325      d5      

Working with Non-Decimal Byte Values

In addition to working with individual bytes as decimal values, you may want to perform bitwise operations with byte values, or work with byte arrays or with the binary or hexadecimal representations of byte values. For example, overloads of the BitConverter.GetBytes method can convert each of the primitive data types to a byte array.

Byte values are represented in 8 bits by their magnitude only, without a sign bit. This is important to keep in mind when you perform bitwise operations on Byte values or when you work with individual bits. In order to perform a numeric, Boolean, or comparison operation on any two non-decimal values, both values must use the same representation.

When an operation is performed on two Byte values, the values share the same representation, so the result is accurate. This is illustrated in the following example, which masks the lowest-order bit of a Byte value to ensure that it is even.

Imports System.Globalization

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim values() As String = {Convert.ToString(12, 16), _
                                 Convert.ToString(123, 16), _
                                 Convert.ToString(245, 16)}

      Dim mask As Byte = &HFE
      For Each value As String In values
         Dim byteValue As Byte = Byte.Parse(value, NumberStyles.AllowHexSpecifier)
         outputBlock.Text += String.Format("{0} And {1} = {2}", byteValue, mask, _
                           byteValue And mask) & vbCrLf
      Next
   End Sub
End Module
' The example displays the following output:
'       12 And 254 = 12
'       123 And 254 = 122
'       245 And 254 = 244

using System;
using System.Globalization;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      string[] values = { Convert.ToString(12, 16), 
                          Convert.ToString(123, 16), 
                          Convert.ToString(245, 16) };

      byte mask = 0xFE;
      foreach (string value in values)
      {
         Byte byteValue = Byte.Parse(value, NumberStyles.AllowHexSpecifier);
         outputBlock.Text += String.Format("{0} And {1} = {2}", byteValue, mask,
                           byteValue & mask) + "\n";
      }
   }
}
// The example displays the following output:
//       12 And 254 = 12
//       123 And 254 = 122
//       245 And 254 = 244

On the other hand, when you work with both unsigned and signed bits, bitwise operations are complicated by the fact that the SByte values use sign-and-magnitude representation for positive values, and two's complement representation for negative values. In order to perform a meaningful bitwise operation, the values must be converted to two equivalent representations, and information about the sign bit must be preserved. The following example does this to mask out bits 2 and 4 of an array of 8-bit signed and unsigned values.

Imports System.Collections.Generic
Imports System.Globalization

Public Structure ByteString
   Public Value As String
   Public Sign As Integer
End Structure

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim values() As ByteString = CreateArray(-15, 123, 245)

      Dim mask As Byte = &H14        ' Mask all bits but 2 and 4.

      For Each strValue As ByteString In values
         Dim byteValue As Byte = Byte.Parse(strValue.Value, NumberStyles.AllowHexSpecifier)
         outputBlock.Text += String.Format("{0} ({1}) And {2} ({3}) = {4} ({5})", _
                           strValue.Sign * byteValue, _
                           Convert.ToString(byteValue, 2), _
                           mask, Convert.ToString(mask, 2), _
                           (strValue.Sign And Math.Sign(mask)) * (byteValue And mask), _
                           Convert.ToString(byteValue And mask, 2)) + vbCrLf
      Next
   End Sub

   Private Function CreateArray(ByVal ParamArray values() As Object) As ByteString()
      Dim byteStrings As New List(Of ByteString)
      For Each value As Object In values
         Dim temp As New ByteString()
         Dim sign As Integer = Math.Sign(value)
         temp.Sign = sign
         ' Change two's complement to magnitude-only representation.
         value = value * sign

         temp.Value = Convert.ToString(value, 16)
         byteStrings.Add(temp)
      Next
      Return byteStrings.ToArray()
   End Function
End Module
' The example displays the following output:
'       -15 (1111) And 20 (10100) = 4 (100)
'       123 (1111011) And 20 (10100) = 16 (10000)
'       245 (11110101) And 20 (10100) = 20 (10100)

using System;
using System.Collections.Generic;
using System.Globalization;

public struct ByteString
{
   public string Value;
   public int Sign;
}

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      ByteString[] values = CreateArray(-15, 123, 245);

      byte mask = 0x14;        // Mask all bits but 2 and 4.

      foreach (ByteString strValue in values)
      {
         byte byteValue = Byte.Parse(strValue.Value, NumberStyles.AllowHexSpecifier);
         outputBlock.Text += String.Format("{0} ({1}) And {2} ({3}) = {4} ({5})",
                           strValue.Sign * byteValue,
                           Convert.ToString(byteValue, 2),
                           mask, Convert.ToString(mask, 2),
                           (strValue.Sign & Math.Sign(mask)) * (byteValue & mask),
                           Convert.ToString(byteValue & mask, 2)) + "\n";
      }
   }

   private static ByteString[] CreateArray(params int[] values)
   {
      List<ByteString> byteStrings = new List<ByteString>();

      foreach (object value in values)
      {
         ByteString temp = new ByteString();
         int sign = Math.Sign((int)value);
         temp.Sign = sign;

         // Change two's complement to magnitude-only representation.
         temp.Value = Convert.ToString(((int)value) * sign, 16);

         byteStrings.Add(temp);
      }
      return byteStrings.ToArray();
   }
}
// The example displays the following output:
//       -15 (1111) And 20 (10100) = 4 (100)
//       123 (1111011) And 20 (10100) = 16 (10000)
//       245 (11110101) And 20 (10100) = 20 (10100)

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

All members of this type are thread safe. Members that appear to modify instance state actually return a new instance initialized with the new value. As with any other type, reading and writing to a shared variable that contains an instance of this type must be protected by a lock to guarantee thread safety.

See Also

Reference

System Namespace

SByte