C# Integers

Summary: in this tutorial, you’ll learn how to use the C# integer types to represent the integer numbers.

Introduction to the C# integers #

Integers are whole numbers for example -1, 0, 1, 2, 3. C# uses the integral numeric types to represent integer numbers. So far, you have learned how to use the int type to declare a variable that holds an integer.

Besides the int type, C# has other integer types with their specific keyword, range, and size.

The following table illustrates the characteristics of all the integer types in C#:

C# type/keyword	Range	Size
`sbyte`	-128 to 127	Signed 8-bit integer
`byte`	0 to 255	Unsigned 8-bit integer
`short`	-32,768 to 32,767	Signed 16-bit integer
`ushort`	0 to 65,535	Unsigned 16-bit integer
`int`	-2,147,483,648 to 2,147,483,647	Signed 32-bit integer
`uint`	0 to 4,294,967,295	Unsigned 32-bit integer
`long`	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	Signed 64-bit integer
`ulong`	0 to 18,446,744,073,709,551,615	Unsigned 64-bit integer

C# also has other two integer types nint and nunit whose ranges depend on the specific platform.

If you declare a variable with an integer type and assign a value that is out of range, you’ll get a compilation error.

For example, the following declares a variable age with the type byte and initializes its value to an invalid value 256:

byte age = 256;

When you compile the code, the compiler issues the following error:

error CS0031: Constant value '256' cannot be converted to a 'byte'

Min and max values #

Each integer type has the MinValue and MaxValue constants that provide the minimum and maximum of the type. To access these values, you use the dot operator (.). For example:

int.MinValue
int.MaxValue

The following displays the range of the int type:

Console.WriteLine($"int range: ({int.MinValue},{int.MaxValue})");

Output:

int range: (-2147483648,2147483647)

Integer literals #

Integer literals can be decimal, hexadecimal, and binary.

Decimal #

The following example shows the integer literals in decimal without any prefix:

int quantity = 10;
int amount = 20;

If a number is big, you can use the digit separator (_) to make it more readable. Note that you can use the digit separator (_) for all integer literals, not just decimal. For example:

int prize = 1_000_000;

Hexadecimal #

Hexadecimal numbers have the 0x or 0X prefix. For example:

int address = 0x5A;

Binary #

Binary numbers have the 0b or 0B prefix. For example:

int flag = 0b10011110;

Also, you can use the digit separator (_) to separate the digits like this:

int flag = 0b_1001_1110;

Summary #

Use C# integer type to represent integer numbers.
Use digit separator (_) with big numbers to make them more readable.

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