C# variables

In C#, a variable is a named storage location that holds a value of a particular data type. Variables are used to store and manipulate data in the code.

To declare a variable in C#, you use the following syntax:

data_type variable_name;

Here, data_type specifies the type of data that the variable can hold (e.g. int, double, string, bool, etc.), and variable_name is the name of the variable.

Here is an example of declaring and initializing variables in C#:

int age;           // declaration
age = 30;          // initialization

double salary = 50000.50;    // declaration and initialization

string name = "John";        // declaration and initialization
bool isEmployed = true;      // declaration and initialization

You can also declare and initialize variables in the same statement, like this:

int x = 10;
double y = 20.5;
string message = "Hello, world!";

Once a variable is declared and initialized, you can use it in expressions and assign new values to it. For example:

int x = 10;
int y = 5;

int sum = x + y;   // sum is 15

x = 20;            // x is now 20

Note that variables in C# are case-sensitive, so age, Age, and AGE are considered three different variables. It's also important to choose meaningful variable names that describe the data they hold.