How to declare a variable in C#

Variable is nothing but a name given to a storage area that our programs can manipulate. Each variable in C# has a specific type, which determines the size and layout of the variable's memory the range of values that can be stored within that memory and the set of operations that can be applied to the variable.

The basic value types provided in C# can be categorized as:

Type	Example
Integral types	sbyte, byte, short, ushort, int, uint, long, ulong, and char
Floating point types	float and double
Decimal types	decimal
Boolean types	true or false values, as assigned
Nullable types	Nullable data types

C# also allows defining other value types of variable such as enum and reference types of variables such as class.

Defining Variables

Syntax for variable definition in C# is:

;

Here, data_type must be a valid C# data type including char, int, float, double, or any user-defined data type, and variable_list may consist of one or more identifier names separated by commas.

Some valid variable definitions are shown here:

int i, j, k; char c, ch; float f, salary; double d;

You can initialize a variable at the time of definition as:

int i = 100;

Initializing Variables

Variables are initialized (assigned a value) with an equal sign followed by a constant expression.

The general form of initialization is:

variable_name = value;

Variables can be initialized in their declaration. The initializer consists of an equal sign followed by a constant expression as :

= value;

Some Examples:

int d = 3, f = 5; /* initializing d and f. */

byte z = 22; /* initializes z. */

double pi = 3.14159; /* declares an approximation of pi. */

char x = 'x'; /* the variable x has the value 'x'. */