C# Language Pocket Reference

Predefined Types

All of C#’s predefined types alias types found in the System namespace. For example, there is only a syntactic difference between these two statements:

int i = 5;
System.Int32 i = 5;

Integral Types

This table lists the integral types and their features:

C# type	System type	Size	Signed
sbyte	System.SByte	1 byte	Yes
short	System.Int16	2 bytes	Yes
int	System.Int32	4 bytes	Yes
long	System.Int64	8 bytes	Yes
byte	System.Byte	1 byte	No
ushort	System.UInt16	2 bytes	No
uint	System.UInt32	4 bytes	No
ulong	System.UInt64	8 bytes	No

For unsigned integers that are n bits wide, possible values range from 0 to 2. For signed integers that are n bits wide, their possible values range from -2^n-1 to 2^n-1-1. Integer literals can use either decimal or hexadecimal notation:

int x = 5;
ulong y = 0x1234AF; // prefix with 0x for hexadecimal

When an integral literal is valid for several possible integral types, the default type that is chosen goes in this order: int, uint, long, and ulong. The following suffixes may be used to specify the chosen type explicitly:

U

uint or ulong

L

long or ulong

UL

ulong

Integral conversions

An implicit conversion between integral types is permitted when the type to which you’d like to convert contains every possible value of the type to convert. Otherwise, an explicit conversion is required. For instance, you can implicitly convert an int to a long, but must explicitly convert an int ...