C# Task Examples

Learn how to efficiently read the content of a text file into a string or process it line by line.

using System;
using System.IO;

public class FileReader
{
    public static void Main(string[] args)
    {
        string filePath = "example.txt";

        try
        {
            // Read the entire file content
            string fileContent = File.ReadAllText(filePath);
            Console.WriteLine("File Content:");
            Console.WriteLine(fileContent);

            // Or read line by line
            Console.WriteLine("\nReading line by line:");
            using (StreamReader sr = new StreamReader(filePath))
            {
                string line;
                while ((line = sr.ReadLine()) != null)
                {
                    Console.WriteLine(line);
                }
            }
        }
        catch (FileNotFoundException)
        {
            Console.WriteLine($"Error: File not found at {filePath}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred: {ex.Message}");
        }
    }
}

Demonstrates how to write text to a file, overwriting existing content or appending to it.

using System;
using System.IO;

public class FileWriter
{
    public static void Main(string[] args)
    {
        string filePath = "output.txt";
        string contentToWrite = "This is the first line.\nThis is the second line.";

        try
        {
            // Write text to the file, overwriting if it exists
            File.WriteAllText(filePath, contentToWrite);
            Console.WriteLine($"Successfully wrote to {filePath}");

            // Append text to the file
            string contentToAppend = "\nThis line is appended.";
            File.AppendAllText(filePath, contentToAppend);
            Console.WriteLine($"Successfully appended to {filePath}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred: {ex.Message}");
        }
    }
}

Understand how to break a string into pieces based on a delimiter and how to combine an array of strings into a single string.

using System;

public class StringManipulation
{
    public static void Main(string[] args)
    {
        string data = "apple,banana,cherry,date";

        // Splitting a string
        char delimiter = ',';
        string[] fruits = data.Split(delimiter);

        Console.WriteLine("Fruits array:");
        foreach (string fruit in fruits)
        {
            Console.WriteLine($"- {fruit}");
        }

        // Joining an array of strings
        string joinedString = string.Join(" - ", fruits);
        Console.WriteLine($"\nJoined string: {joinedString}");
    }
}

A guide to using `List` for dynamic collections, including adding, removing, and iterating through elements.

using System;
using System.Collections.Generic;

public class ListExample
{
    public static void Main(string[] args)
    {
        // Creating a list of strings
        List names = new List();

        // Adding elements
        names.Add("Alice");
        names.Add("Bob");
        names.Add("Charlie");

        Console.WriteLine("Initial list:");
        foreach (string name in names)
        {
            Console.WriteLine(name);
        }

        // Removing an element
        names.Remove("Bob");
        Console.WriteLine("\nList after removing Bob:");
        foreach (string name in names)
        {
            Console.WriteLine(name);
        }

        // Inserting an element
        names.Insert(1, "David");
        Console.WriteLine("\nList after inserting David:");
        foreach (string name in names)
        {
            Console.WriteLine(name);
        }
    }
}