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Reversing the Order of Lines in a Text File Using C#

In this exercise, you will create a program that reads a text file, reverses the order of its lines, and writes the reversed content into a new output file. This exercise is designed to help you practice file handling in C#, including reading from and writing to text files efficiently.

You will begin by reading all lines from an input text file and storing them in a suitable data structure. After that, you will reverse the order of these lines and write the reversed content into a new output file. This will allow you to understand how to manipulate text data effectively in C#.

By completing this exercise, you will gain experience working with file I/O operations, including reading, writing, and processing text efficiently. These skills are essential for handling file-based data storage and manipulation in real-world applications.



Group

Dynamic Memory Management in C#

Objective

1. Read the lines from an input text file.
2. Store the lines in a data structure.
3. Reverse the order of the stored lines.
4. Write the reversed lines into an output text file.

In this exercise, you need to create a program that reads from a text file and stores it to another text file by reversing the order of the lines. This exercise will allow you to practice text file manipulation in C# and work with efficient data reading and writing.

For this exercise, you will be provided with an input text file with the following format: 

yesterday Real Madrid  

won against  

Barcelona FC


After processing the file, you will need to create an output file with the same content but with the lines in reverse order, so the output file will have the following format: 
Barcelona FC  

won against  

yesterday Real Madrid


This exercise is useful for understanding how to read and write files in C#, as well as how to work with basic string and file manipulation operations in the system.

Example C# Exercise

 Copy C# Code 
using System;
using System.IO; // Import the namespace for file handling

class Program
{
    static void Main()
    {
        // Define the input and output file paths
        string inputFilePath = "input.txt";  
        string outputFilePath = "output.txt";

        // Check if the input file exists before proceeding
        if (File.Exists(inputFilePath))
        {
            // Read all lines from the input file
            string[] lines = File.ReadAllLines(inputFilePath);

            // Reverse the order of the lines
            Array.Reverse(lines);

            // Write the reversed lines into the output file
            File.WriteAllLines(outputFilePath, lines);

            // Inform the user that the process is complete
            Console.WriteLine("The file has been processed successfully.");
        }
        else
        {
            // Display an error message if the input file does not exist
            Console.WriteLine("Error: The input file does not exist.");
        }
    }
}

 Output

//Code Output:
The file has been processed successfully.

//Contents of output.txt after execution:
Barcelona FC  
won against  
yesterday Real Madrid

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More C# Practice Exercises of Dynamic Memory Management in C#

Explore our set of C# Practice Exercises! Specifically designed for beginners, these exercises will help you develop a solid understanding of the basics of C#. From variables and data types to control structures and simple functions, each exercise is crafted to challenge you incrementally as you build confidence in coding in C#.