Mix and sort files C# Exercise - C# Programming Course

// Importing necessary namespaces for file operations and basic collections
using System;  // Basic namespace for console input/output and fundamental operations
using System.Collections.Generic;  // For using collections like List
using System.IO;  // For file reading and writing operations

class Program
{
    // Function to read the contents of a file, split them into words, and return a sorted list
    static List ReadAndSortFile(string filePath)
    {
        // Check if the file exists before trying to read it
        if (File.Exists(filePath))  // If the file exists
        {
            // Read all lines from the file and split them into words
            string[] words = File.ReadAllText(filePath).Split(new[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries);  // Read all text from the file and split by spaces and line breaks

            // Convert the array of words into a list and sort it alphabetically
            List sortedWords = new List(words);  // Create a list from the words array
            sortedWords.Sort();  // Sort the list alphabetically

            return sortedWords;  // Return the sorted list of words
        }
        else
        {
            Console.WriteLine($"The file {filePath} does not exist.");  // Print a message if the file does not exist
            return new List();  // Return an empty list if the file is not found
        }
    }

    // Main program method to read, merge, and sort the contents of two files
    static void Main(string[] args)
    {
        // Define the paths to the two input files
        string filePath1 = "file1.txt";  // Path for the first input file
        string filePath2 = "file2.txt";  // Path for the second input file

        // Read and sort the contents of both files
        List sortedWords1 = ReadAndSortFile(filePath1);  // Read and sort the first file
        List sortedWords2 = ReadAndSortFile(filePath2);  // Read and sort the second file

        // Merge the two sorted lists
        sortedWords1.AddRange(sortedWords2);  // Add the words from the second file to the first

        // Sort the merged list alphabetically
        sortedWords1.Sort();  // Sort the merged list alphabetically

        // Display the sorted words in the console
        Console.WriteLine("Merged and sorted words:");
        foreach (string word in sortedWords1)  // Iterate through the sorted words
        {
            Console.Write(word + " ");  // Display each word followed by a space
        }

        Console.WriteLine();  // Add a line break after the output
    }
}