byte and sbyte Types
This page was last reviewed on May 3, 2023.
Dot Net Perls
Byte. The C# byte type (which is 8 bits) is a compact and efficient type. Byte arrays are useful more often than single bytes—they can store file data.
Byte versus sbyte. To make matters more complex, a byte has no sign bit, but an sbyte does. We can use an sbyte when negative numbers are needed.
byte Array
First example. Byte is a value type. When used as a local variable, its storage location is directly contained in the evaluation stack. It can hold any value between 0 and 255.
Part 1 We declare a byte variable with the name "value." The variable is assigned the integer value 5.
Part 2 We display the minimum and maximum values of the byte type. These are 0 and 255.
Part 3 The typeof operator returns a managed pointer (System.Byte). The default value of byte is equal to zero.
typeof, nameof
using System; // Part 1: assign an integer to a byte variable. byte value = 5; Console.WriteLine(value); // Part 2: display minimum value and maximum value. Console.WriteLine(byte.MinValue); Console.WriteLine(byte.MaxValue); // Part 3: use Type pointer and default value. Console.WriteLine(typeof(byte)); Console.WriteLine(typeof(Byte)); // Uppercase Byte Console.WriteLine(default(byte));
5 0 255 System.Byte System.Byte 0
MinValue. The minimum value (byte.MinValue) is equal to zero. And the maximum value (byte.MaxValue) is equal to 255. A value greater than 255 will cause an overflow error.
byte.MinValue = 0 byte.MaxValue = 255
sbyte.MinValue = -128 sbyte.MaxValue = 127
Convert int to byte. Suppose we want to copy some ints to a byte array, and we want to be sure the ints can all be represented as bytes. We can use a checked block for the cast.
Step 1 We create a byte array. We will be storing ints in the byte array, but do not want any issues with over flow.
Step 2 We loop over a range of numbers. We will be storing these ints inside the byte array.
Step 3 We cast the int to a byte inside a checked statement. If it does not fit, an exception will occur, and we can fix the bug.
using System; // Step 1: create empty byte array. byte[] array = new byte[100]; int write = 0; // Step 2: loop over some numbers. for (int i = 20; i < 40; i++) { // Step 3: safely cast int to byte. // ... Store byte in array. checked { array[write++] = (byte)i; } } Console.WriteLine("DONE");
Arguments. The C# compiler will treat some numbers as bytes in a program. So it passes the value 10 as a byte value. But it cannot treat 1000 as a byte, so it causes an error.
Tip The compiler uses a special type of error, a compile-time error, to prevent incorrect programs from ever running.
using System; class Program { static void Main() { // The 10 is automatically treated as a byte. Test(10); // This does not compile: // Test(1000); } static void Test(byte value) { Console.WriteLine(value); } }
Sbyte. This signed byte type represents a small integer that can be negative or positive. It is 8 bits or 1 byte and it stores integers between -128 and 127. It is less commonly used.
Info This program tests and increments as byte. It prints the size, and shows the minimum and maximum values.
And The program uses logic to return the Type and TypeCode associated with the sbyte type.
Tip You can assign and increment sbytes just like any other value type. An unassigned sbyte on the heap will be initialized to 0.
using System; sbyte val = 1; // Local variable. Console.WriteLine("val: {0}", val); Console.WriteLine("sizeof: {0}", sizeof(sbyte)); Console.WriteLine("default: {0}", default(sbyte)); Console.WriteLine("min: {0}", sbyte.MinValue); Console.WriteLine("max: {0}", sbyte.MaxValue); Console.WriteLine("type: {0}", val.GetType()); Console.WriteLine("code: {0}", val.GetTypeCode()); if (val == 1) // Test. { Console.WriteLine("1: {0}", true); } val++; // Increment. Console.WriteLine("val: {0}", val);
val: 1 sizeof: 1 default: 0 min: -128 max: 127 type: System.SByte code: SByte 1: True val: 2
The sbyte type does not provide any low-level functionality that the byte type does not also have. But it can improve interoperability with other libraries.
Tip Because both sbyte and byte represent 8 bits, you can store the bits in either type with no data loss.
Tip 2 If a program uses signed bytes, though, the data will make more sense if you treat one of the bits as a sign bit by using sbyte.
Char. There are some types that are related to, or similar to, the byte type. In programming languages such as C or C++, the char type is only one byte.
However In .NET, the System.Char type is two bytes and requires twice as much storage.
Tip The ushort type is another small integer type. It is best to use the smallest type that fits your range of data.
short, ushort
BitArray. Bytes have eight bits. But if we only need a true or false value, we can use a single bit. A BitArray can greatly reduce memory usage over a byte array.
A review. Byte variables can contain the values between 0 and 255. The type is a value type. Sbyte meanwhile can accommodate negative numbers.
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
This page was last updated on May 3, 2023 (rewrite).
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