Function tasks database C# Exercise - C# Programming Course

// Importing necessary namespaces
using System;
using System.Collections.Generic;

class Program
{
    // List to store tasks
    static List tasks = new List();

    // Main method to drive the program
    public static void Main()
    {
        // Display the menu and interact with the user
        int choice;
        do
        {
            choice = DisplayMenu();
            HandleMenuChoice(choice);
        }
        while (choice != 4); // Exit the loop when user chooses to quit
    }

    // Display menu to the user
    public static int DisplayMenu()
    {
        // Display available options
        Console.WriteLine("\nTask Manager");
        Console.WriteLine("1. Add a new task");
        Console.WriteLine("2. View all tasks");
        Console.WriteLine("3. Remove a task");
        Console.WriteLine("4. Exit");
        Console.Write("Enter your choice: ");
        string input = Console.ReadLine();
        
        // Try to parse user input to an integer
        if (int.TryParse(input, out int choice))
        {
            return choice;
        }
        else
        {
            Console.WriteLine("Invalid choice, please try again.");
            return 0; // Return invalid choice to keep the menu displayed
        }
    }

    // Handle user's menu choice
    public static void HandleMenuChoice(int choice)
    {
        switch (choice)
        {
            case 1:
                AddTask(); // Call the AddTask function
                break;
            case 2:
                ViewTasks(); // Call the ViewTasks function
                break;
            case 3:
                RemoveTask(); // Call the RemoveTask function
                break;
            case 4:
                Console.WriteLine("Exiting..."); // Exit message
                break;
            default:
                Console.WriteLine("Invalid choice, please try again."); // Invalid choice handling
                break;
        }
    }

    // Add a new task to the list
    public static void AddTask()
    {
        Console.Write("Enter the task description: ");
        string task = Console.ReadLine();
        
        if (!string.IsNullOrEmpty(task))
        {
            tasks.Add(task); // Add the task to the list
            Console.WriteLine("Task added successfully.");
        }
        else
        {
            Console.WriteLine("Task description cannot be empty.");
        }
    }

    // Display all tasks in the list
    public static void ViewTasks()
    {
        if (tasks.Count == 0)
        {
            Console.WriteLine("No tasks available.");
        }
        else
        {
            Console.WriteLine("\nTasks:");
            for (int i = 0; i < tasks.Count; i++)
            {
                Console.WriteLine($"{i + 1}. {tasks[i]}"); // Display task with its index
            }
        }
    }

    // Remove a task from the list
    public static void RemoveTask()
    {
        Console.Write("Enter the number of the task to remove: ");
        string input = Console.ReadLine();
        
        if (int.TryParse(input, out int taskNumber) && taskNumber > 0 && taskNumber <= tasks.Count)
        {
            tasks.RemoveAt(taskNumber - 1); // Remove task by its index (1-based to 0-based index)
            Console.WriteLine("Task removed successfully.");
        }
        else
        {
            Console.WriteLine("Invalid task number.");
        }
    }
}