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.

  code reference: System.Byte.Instantiation#1

• 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 Option Strict is on. If the non-byte value is a float, double, or decimal value that includes a fractional component, the handling of its fractional part depends on the compiler performing the conversion. The following example assigns several numeric values to byte variables.

  code reference: System.Byte.Instantiation#2

• 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 int values to byte values.

  code reference: System.Convert.ToByte#4

• You can call the byte.Parse(string) or byte.TryParse(string, Byte@) 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.

  code reference: System.Byte.Instantiation#3

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 byte.CompareTo(byte) or byte.Equals(byte) method.

You can also call the members of the Math class to perform a wide range of numeric operations, including getting the absolute value of a number, calculating the quotient and remainder from integral division, determining the maximum or minimum value of two integers, getting the sign of a number, and rounding a number.

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 byte.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.

code reference: System.Byte.Formatting#1

You can also format a byte value as a binary, octal, decimal, or hexadecimal string by calling the Convert.ToString(byte, int) 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.

code reference: System.Byte.Formatting#2

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(int) method can convert each of the primitive data types to a byte array, and the System.Numerics.BigInteger.ToByteArray method converts a System.Numerics.BigInteger value 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.

code reference: System.Byte.Bitwise#1

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.

code reference: System.Byte.Bitwise#2

This type is safe for multithreaded operations.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0