uint (C# Reference)


Updated: July 20, 2015

For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.

The uint keyword signifies an integral type that stores values according to the size and range shown in the following table.

TypeRangeSize.NET Framework type
uint0 to 4,294,967,295Unsigned 32-bit integerSystem.UInt32

Note The uint type is not CLS-compliant. Use int whenever possible.

You can declare and initialize a variable of the type uint like this example:

uint myUint = 4294967290;  

When an integer literal has no suffix, its type is the first of these types in which its value can be represented: int, uint, long, ulong. In this example, it is uint:

uint uInt1 = 123;  

You can also use the suffix u or U, such as this:

uint uInt2 = 123U;  

When you use the suffix U or u, the type of the literal is determined to be either uint or ulong according to the numeric value of the literal. For example:


This code displays System.UInt32, followed by System.UInt64 -- the underlying types for uint and ulong respectively -- because the second literal is too large to be stored by the uint type.

There is a predefined implicit conversion from uint to long, ulong, float, double, or decimal. For example:

float myFloat = 4294967290;   // OK: implicit conversion to float  

There is a predefined implicit conversion from byte, ushort, or char to uint. Otherwise you must use a cast. For example, the following assignment statement will produce a compilation error without a cast:

long aLong = 22;  
// Error -- no implicit conversion from long:  
uint uInt1 = aLong;   
// OK -- explicit conversion:  
uint uInt2 = (uint)aLong;  

Notice also that there is no implicit conversion from floating-point types to uint. For example, the following statement generates a compiler error unless an explicit cast is used:

// Error -- no implicit conversion from double:  
uint x = 3.0;  
// OK -- explicit conversion:  
uint y = (uint)3.0;   

For information about arithmetic expressions with mixed floating-point types and integral types, see float and double.

For more information about implicit numeric conversion rules, see the Implicit Numeric Conversions Table.

For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.

C# Reference
C# Programming Guide
C# Keywords
Integral Types Table
Built-In Types Table
Implicit Numeric Conversions Table
Explicit Numeric Conversions Table