C# Tutorial 3.3 : Constants

 In C#, constants are used to represent values that do not change during the execution of a program. They provide a way to define values that remain constant throughout the program's lifecycle. Let's dive into how to declare and use constants in C#.

1. Declaring Constants:

In C#, you declare a constant using the const keyword followed by the data type, the constant name, and the value.

using System;

class Program

{

    // Declaring integer constant

    const int MaxAttempts = 3;

    static void Main()

    {

        // Attempt to change the value of a constant (will result in a compilation error)

        // MaxAttempts = 5;

        // Displaying the value of the constant

        Console.WriteLine($"Maximum Attempts Allowed: {MaxAttempts}");

        // Other code...

    }

}

In this example, MaxAttempts is a constant of type int with a value of 3. Note that attempting to change the value of a constant after it has been assigned will result in a compilation error.

2. Benefits of Constants:

• Readability: Constants improve code readability by providing meaningful names for values used in your program.

• Maintenance: If a value needs to be changed, you only need to update it at the constant declaration, and the change will be reflected throughout the code.

3. Constants in Different Scopes:

Constants can be declared at various levels, including within a method, inside a class, or even at the namespace level. The scope of a constant determines where it can be accessed.

using System;

class Program

{

    // Class-level constant

    const double Pi = 3.14159265359;

    static void Main()

    {

        // Method-level constant

        const int MaxValue = 100;

        // Displaying the values

        Console.WriteLine($"Pi: {Pi}");

        Console.WriteLine($"Max Value: {MaxValue}");

        // Other code...

    }

}

In this example, Pi is a class-level constant, and MaxValue is a method-level constant.

4. Naming Conventions for Constants:

By convention, constant names are written in uppercase letters with underscores separating words.

const int MAX_VALUE = 100;

5. Run the Program:

Press F5 or click the "Start Debugging" button to build and run your program. The output should display the values of the constants.

6. Experiment:

• Declare constants of different data types (int, double, string, etc.).
• Try using constants in different scopes to understand their accessibility.

Congratulations! You've learned how to declare and use constants in C#. In the next tutorial, we'll explore control flow statements, starting with if statements.