What are variables in C#

What are Variables?

Variables in C# are like containers that hold data that can be used and manipulated throughout your code. Each variable has a name, a type, and a value. The type of a variable defines what kind of data it can hold, such as numbers, text, or more complex structures.

Another Definition for Variable : In C#, a variable is a named memory location in RAM used to store a specific type of value during the execution of a program. This value can be accessed, modified, and used in calculations throughout the program.

Declaring Variables

To declare a variable in C#, you need to specify its type followed by the variable’s name. Here’s a simple example:

type variableName = value;

int age =20;

In this example:

• int is the type of data, indicating that age will store an integer.
• age is the variable name.

Naming Conventions

Choosing clear and meaningful variable names is essential for readability and maintainability. Follow these guidelines:

• Start with a letter: Avoid using numbers or special characters at the beginning.
• Camel Case: For local variables and method parameters, start with a lowercase letter and capitalize the first letter of subsequent words (e.g., userName).
• Descriptive Names: Use names that describe the variable’s purpose (e.g., totalAmount instead of x).

Variable Scope and Lifetime

Scope refers to where a variable can be accessed in your code, while lifetime is how long a variable exists in memory.

• Local Scope: Variables declared inside a method are only accessible within that method.

Example:

void DisplayMessage()
{
    string message = "Hello, World!";
    Console.WriteLine(message);
}

• Class Scope: Variables declared at the class level (fields) are accessible by all methods within the class.

Example:

class Person
{
    private string name;  // Here variable is "name" and data type is string

    public void SetName(string newName)
    {
        name = newName;
    }

    public void DisplayName()
    {
        Console.WriteLine(name);
    }
}

Note: Don’t scare here what is class and what method, upcoming lessons you can learn methods and classes. Also in C# different data types available to store the different data variables, next lesson you will learn DataTypes in C#.