How to Use Copilot for Code Commenting and Documentation

Writing code comments and documentation is often overlooked by developers, yet it plays a crucial role in making code readable, maintainable, and easier to understand, especially for teams. Good documentation helps new developers get up to speed quickly and ensures that existing code remains easy to modify and debug.

With GitHub Copilot, developers can automate the process of adding comments and documentation, saving time and effort. This article explores how Copilot can assist in commenting on and documenting your code efficiently.

Commenting code using Copilot

You can use Copilot to add comments to your code by simply asking Copilot.

The following prompt adds comments to the Author class.

The following prompt comments entire program.

Now, the updated program is listed in Listing 2.

// Represents an author with properties for name, email, and country
class Author
{
    public string Name { get; set; }
    public string Email { get; set; }
    public string Country { get; set; }
}

class Program
{
    static void Main()
    {
        // Specify the file path
        string filePath = "C:/temp/CSharpCorner.txt";

        // Initialize character and word count variables
        int characterCount = 0;
        int wordCount = 0;

        try
        {
            // Read the file line by line
            using (StreamReader sr = new StreamReader(filePath))
            {
                string line;
                while ((line = sr.ReadLine()) != null)
                {
                    // Update character count
                    characterCount += line.Length;

                    // Split the line into words and update word count
                    wordCount += line.Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries).Length;
                }
            }

            // Display the total number of characters and words
            Console.WriteLine($"Total number of characters: {characterCount}");
            Console.WriteLine($"Total number of words: {wordCount}");
        }
        catch (FileNotFoundException)
        {
            // Handle file not found exception
            Console.WriteLine("File not found.");
        }
        catch (Exception ex)
        {
            // Handle other exceptions
            Console.WriteLine($"An error occurred: {ex.Message}");
        }

        // Accept input from the console
        Console.WriteLine("Enter author details:");
        Console.Write("Name: ");
        string name = Console.ReadLine();
        Console.Write("Email: ");
        string email = Console.ReadLine();
        Console.Write("Country: ");
        string country = Console.ReadLine();

        // Create an instance of the Author class
        Author author = new Author
        {
            Name = name,
            Email = email,
            Country = country
        };

        // Call the AddAuthorToFile method to append author details to the file
        AddAuthorToFile(filePath, author);
    }

    // Method to read the file line by line and display each line
    public static void ReadLineByLine(string filePath)
    {
        using (StreamReader sr = new StreamReader(filePath))
        {
            string line;
            while ((line = sr.ReadLine()) != null)
            {
                Console.WriteLine(line);
            }
        }
    }

    // Method to read all lines from the file and display each line
    public static void ReadAllLines(string filePath)
    {
        string[] lines = File.ReadAllLines(filePath);
        foreach (string line in lines)
        {
            Console.WriteLine(line);
        }
    }

    // Method to append author details to the file
    public static void AddAuthorToFile(string filePath, Author author)
    {
        using (StreamWriter sw = new StreamWriter(filePath, true))
        {
            sw.WriteLine($"Name: {author.Name}");
            sw.WriteLine($"Email: {author.Email}");
            sw.WriteLine($"Country: {author.Country}");
            sw.WriteLine();
        }
    }
}

Now only can you comment your existing code but can also ask to remove existing comments.

The following prompt removes all existing comments from the program.

Once you accept the changes, all comments from the code will be removed.

You can also add detailed documentation to the program by using the following prompt.

Note. You can also go to a specific class, method, and code line by typing a prompt specifically about that code block.

The final code

// Represents an author with properties for name, email, and country
class Author
{
    public string Name { get; set; }
    public string Email { get; set; }
    public string Country { get; set; }
}

class Program
{
    /// <summary>
    /// Entry point of the program.
    /// </summary>
    static void Main()
    {
        // Specify the file path
        string filePath = "C:/temp/CSharpCorner.txt";

        // Initialize character and word count variables
        int characterCount = 0;
        int wordCount = 0;

        try
        {
            // Read the file using a StreamReader
            using (StreamReader sr = new StreamReader(filePath))
            {
                string line;
                while ((line = sr.ReadLine()) != null)
                {
                    // Update character count
                    characterCount += line.Length;

                    // Split the line into words and update word count
                    wordCount += line.Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries).Length;
                }
            }

            // Print the total number of characters and words
            Console.WriteLine("Total number of characters: " + characterCount);
            Console.WriteLine("Total number of words: " + wordCount);
        }
        catch (FileNotFoundException)
        {
            // Handle file not found exception
            Console.WriteLine("File not found.");
        }
        catch (Exception ex)
        {
            // Handle other exceptions
            Console.WriteLine("An error occurred: " + ex.Message);
        }

        // Prompt the user to enter author details
        Console.WriteLine("Enter author details:");
        Console.Write("Name: ");
        string name = Console.ReadLine();
        Console.Write("Email: ");
        string email = Console.ReadLine();
        Console.Write("Country: ");
        string country = Console.ReadLine();

        // Create an Author object with the entered details
        Author author = new Author
        {
            Name = name,
            Email = email,
            Country = country
        };

        // Add the author details to the file
        AddAuthorToFile(filePath, author);
    }

    /// <summary>
    /// Reads the file line by line and prints each line to the console.
    /// </summary>
    /// <param name="filePath">The path of the file to read.</param>
    public static void ReadLineByLine(string filePath)
    {
        // Read the file using a StreamReader
        using (StreamReader sr = new StreamReader(filePath))
        {
            string line;
            while ((line = sr.ReadLine()) != null)
            {
                // Print each line to the console
                Console.WriteLine(line);
            }
        }
    }

    /// <summary>
    /// Reads all lines from the file and prints each line to the console.
    /// </summary>
    /// <param name="filePath">The path of the file to read.</param>
    public static void ReadAllLines(string filePath)
    {
        // Read all lines from the file
        string[] lines = File.ReadAllLines(filePath);

        // Print each line to the console
        foreach (string line in lines)
        {
            Console.WriteLine(line);
        }
    }

    /// <summary>
    /// Adds the author details to the file.
    /// </summary>
    /// <param name="filePath">The path of the file to write.</param>
    /// <param name="author">The author object containing the details.</param>
    public static void AddAuthorToFile(string filePath, Author author)
    {
        // Write the author details to the file using a StreamWriter
        using (StreamWriter sw = new StreamWriter(filePath, true))
        {
            sw.WriteLine($"Name: {author.Name}");
            sw.WriteLine($"Email: {author.Email}");
            sw.WriteLine($"Country: {author.Country}");
            sw.WriteLine();
        }
    }
}

Documentation using Copilot

Copilot is very helpful in explaining code and writing a blog or documentation about existing code. This is very useful when you are a new member of an existing project and want to understand the project. Copilot can help you explain the code in no time.

If you write blogs and share articles, you can ask Copilot to write for you. However, I highly recommend you get the Copilot content and change it to your own style and voice.

Here is the prompt that can ask Copilot to write a blog for your program.

And this is what I got in the reply for our existing program.

Certainly! Here's a detailed blog about the program.

Download Copilot eBook: Copilot Handbook for Students and Developers