Integral numeric types (C# reference)

The integral numeric types represent integer numbers. All integral numeric types are value types. They’re also simple types and can be initialized with literals. All integral numeric types support arithmetic, bitwise logical, comparison, and equality operators.

Characteristics of the integral types

C# supports the following predefined integral types:

C# type/keyword Range Size .NET type sbyte -128 to 127 Signed 8-bit integer System.SByte byte 0 to 255 Unsigned 8-bit integer System.Byte short -32,768 to 32,767 Signed 16-bit integer System.Int16 ushort 0 to 65,535 Unsigned 16-bit integer System.UInt16 int -2,147,483,648 to 2,147,483,647 Signed 32-bit integer System.Int32 uint 0 to 4,294,967,295 Unsigned 32-bit integer System.UInt32 long -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 Signed 64-bit integer System.Int64 ulong 0 to 18,446,744,073,709,551,615 Unsigned 64-bit integer System.UInt64 nint Depends on platform (computed at runtime) Signed 32-bit or 64-bit integer System.IntPtr nuint Depends on platform (computed at runtime) Unsigned 32-bit or 64-bit integer System.UIntPtr

In all of the table rows except the last two, each C# type keyword from the leftmost column is an alias for the corresponding .NET type. The keyword and .NET type name are interchangeable. For example, the following declarations declare variables of the same type:

int a = 123; System.Int32 b = 123;

The nint and nuint types in the last two rows of the table are native-sized integers. Starting in C# 9.0, you can use the nint and nuint keywords to define native-sized integers. These are 32-bit integers when running in a 32-bit process, or 64-bit integers when running in a 64-bit process. They can be used for interop scenarios, low-level libraries, and to optimize performance in scenarios where integer math is used extensively.

The native-sized integer types are represented internally as the .NET types System.IntPtr and System.UIntPtr. Starting in C# 11, the nint and nuint types are aliases for the underlying types.

The default value of each integral type is zero, 0.

Each of the integral types has MinValue and MaxValue properties that provide the minimum and maximum value of that type. These properties are compile-time constants except for the case of the native-sized types (nint and nuint). The MinValue and MaxValue properties are calculated at runtime for native-sized types. The sizes of those types depend on the process settings.

Use the System.Numerics.BigInteger structure to represent a signed integer with no upper or lower bounds.

Integer literals

Integer literals can be

  • decimal: without any prefix
  • hexadecimal: with the 0x or 0X prefix
  • binary: with the 0b or 0B prefix

The following code demonstrates an example of each:

var decimalLiteral = 42; var hexLiteral = 0x2A; var binaryLiteral = 0b_0010_1010;

The preceding example also shows the use of _ as a digit separator. You can use the digit separator with all kinds of numeric literals.

The type of an integer literal is determined by its suffix as follows:

  • If the literal has no suffix, its type is the first of the following types in which its value can be represented: int, uint, long, ulong.

  • If the literal is suffixed by U or u, its type is the first of the following types in which its value can be represented: uint, ulong.

  • If the literal is suffixed by L or l, its type is the first of the following types in which its value can be represented: long, ulong.

  • If the literal is suffixed by UL, Ul, uL, ul, LU, Lu, lU, or lu, its type is ulong.

If the value represented by an integer literal exceeds UInt64.MaxValue, a compiler error CS1021 occurs.

If the determined type of an integer literal is int and the value represented by the literal is within the range of the destination type, the value can be implicitly converted to sbyte, byte, short, ushort, uint, ulong, nint or nuint:

byte a = 17; byte b = 300; // CS0031: Constant value ‘300’ cannot be converted to a ‘byte’

As the preceding example shows, if the literal’s value isn’t within the range of the destination type, a compiler error CS0031 occurs.

You can also use a cast to convert the value represented by an integer literal to the type other than the determined type of the literal:

var signedByte = (sbyte)42; var longVariable = (long)42;

Conversions

You can convert any integral numeric type to any other integral numeric type. If the destination type can store all values of the source type, the conversion is implicit. Otherwise, you need to use a cast expression to perform an explicit conversion. For more information, see Built-in numeric conversions.

Native sized integers

Native sized integer types have special behavior because the storage is determined by the natural integer size on the target machine.

  • To get the size of a native-sized integer at run time, you can use sizeof(). However, the code must be compiled in an unsafe context. For example:

    Console.WriteLine($”size of nint = {sizeof(nint)}”); Console.WriteLine($”size of nuint = {sizeof(nuint)}”); // output when run in a 64-bit process //size of nint = 8 //size of nuint = 8 // output when run in a 32-bit process //size of nint = 4 //size of nuint = 4

    You can also get the equivalent value from the static IntPtr.Size and UIntPtr.Size properties.

  • To get the minimum and maximum values of native-sized integers at run time, use MinValue and MaxValue as static properties with the nint and nuint keywords, as in the following example:

    Console.WriteLine($”nint.MinValue = {nint.MinValue}”); Console.WriteLine($”nint.MaxValue = {nint.MaxValue}”); Console.WriteLine($”nuint.MinValue = {nuint.MinValue}”); Console.WriteLine($”nuint.MaxValue = {nuint.MaxValue}”); // output when run in a 64-bit process //nint.MinValue = -9223372036854775808 //nint.MaxValue = 9223372036854775807 //nuint.MinValue = 0 //nuint.MaxValue = 18446744073709551615 // output when run in a 32-bit process //nint.MinValue = -2147483648 //nint.MaxValue = 2147483647 //nuint.MinValue = 0 //nuint.MaxValue = 4294967295

  • You can use constant values in the following ranges:

    • For nint: Int32.MinValue to Int32.MaxValue.
    • For nuint: UInt32.MinValue to UInt32.MaxValue.
  • The compiler provides implicit and explicit conversions to other numeric types. For more information, see Built-in numeric conversions.

  • There’s no direct syntax for native-sized integer literals. There’s no suffix to indicate that a literal is a native-sized integer, such as L to indicate a long. You can use implicit or explicit casts of other integer values instead. For example:

    nint a = 42 nint a = (nint)42;

C# language specification

For more information, see the following sections of the C# language specification:

  • Integral types
  • Integer literals
  • C# 9 – Native sized integral types
  • C# 11 – Numeric IntPtr and `UIntPtr

See also

  • C# reference
  • Value types
  • Floating-point types
  • Standard numeric format strings
  • Numerics in .NET