Function tasks database Learn programming C#

Lesson:

Functions


Exercise:

Function tasks database


Objetive:

Create an improved version of the "tasks database", splitting it into functions.


Code:

using System;
public class exercise117
{
    struct DateType
    {
        public ushort year;
        public byte month;
        public byte day;
    }

    struct TaskType
    {
        public DateType date;
        public string description;
        public byte level;
        public string category;
    }

    static int counter = 0;
    static int capacity = 2000;
    static TaskType[] tasks = new TaskType[capacity];

    public static void Add()
    {
        if (counter < capacity)
        {
            Console.Write("Enter the Description of the task: ");
            tasks[counter].description = Console.ReadLine();

            Console.Write("Enter the Level of the task (1-10): ");
            tasks[counter].level = Convert.ToByte(Console.ReadLine());

            Console.Write("Enter the Category of the task: ");
            tasks[counter].category = Console.ReadLine();

            do
            {
                Console.Write("Enter the Day of the task (1 to 31): ");
                tasks[counter].date.day = Convert.ToByte(Console.ReadLine());
                if (tasks[counter].date.day < 1 || tasks[counter].date.day > 31)
                    Console.WriteLine("Not a valid day!");
            }
            while (tasks[counter].date.day < 1 || tasks[counter].date.day > 31);

            do
            {
                Console.Write("Enter the Month of the task (1 to 12): ");
                tasks[counter].date.month = Convert.ToByte(Console.ReadLine());
                if (tasks[counter].date.month < 1 || tasks[counter].date.month > 12)
                    Console.WriteLine("Not a valid month!");
            }
            while (tasks[counter].date.month < 1 || tasks[counter].date.month > 12);

            do
            {
                Console.Write("Enter the Year of the task: ");
                tasks[counter].date.year = Convert.ToUInt16(Console.ReadLine());
                if (tasks[counter].date.year < 1000 || tasks[counter].date.year > 3000)
                    Console.WriteLine("Not a valid year!");
            }
            while (tasks[counter].date.year < 1000 || tasks[counter].date.year > 3000);
            counter++;
        }
        else
            Console.WriteLine("Database full.");
    }

    public static void Show()
    {
        if (counter >= 1)
        {
            byte startDay, startMonth;
            ushort startYear;
            byte endDay, endMonth;
            ushort endYear;

            Console.WriteLine("Starting day: ");
            string number = Console.ReadLine();

            if (number == "")
                startDay = Convert.ToByte(DateTime.Now.Day);
            else
                startDay = Convert.ToByte(number);

            Console.WriteLine("Starting month: ");
            number = Console.ReadLine();
            if (number == "")
                startMonth = Convert.ToByte(DateTime.Now.Month);
            else
                startMonth = Convert.ToByte(number);

            Console.WriteLine("Starting year: ");
            number = Console.ReadLine();
            if (number == "")
                startYear = Convert.ToUInt16(DateTime.Now.Year);
            else
                startYear = Convert.ToUInt16(number);

            Console.WriteLine("Final day: ");
            number = Console.ReadLine();
            if (number == "")
                endDay = Convert.ToByte(DateTime.Now.Day);
            else
                endDay = Convert.ToByte(number);

            Console.WriteLine("Final month: ");
            number = Console.ReadLine();
            if (number == "")
                endMonth = Convert.ToByte(DateTime.Now.Month);
            else
                endMonth = Convert.ToByte(number);

            Console.WriteLine("Final year: ");
            number = Console.ReadLine();
            if (number == "")
                endYear = Convert.ToUInt16(DateTime.Now.Year);
            else
                endYear = Convert.ToUInt16(number);

            string startDate = "" + startYear +
                startMonth.ToString("00") + startDay.ToString("00");
            string endDate = "" + endYear +
                endMonth.ToString("00") + endDay.ToString("00");

            for (int i = 0; i < counter; i++)
            {
                string currentDate = "" + tasks[i].date.year +
                    tasks[i].date.month.ToString("00") + tasks[i].date.day.ToString("00");
                if (currentDate.CompareTo(startDate) >= 0 && currentDate.CompareTo(endDate) <= 0)
                {
                    Console.WriteLine("The number is {0}: {1}/{2}/" +
                        "{3} - {4} - {5} - {6}.", i + 1,
                        tasks[i].date.day, tasks[i].date.month,
                        tasks[i].date.year, tasks[i].description,
                        tasks[i].category, tasks[i].level);
                }
            }
        }
        else
            Console.WriteLine("Database empty.");
    }

    public static void Find()
    {
        string search;
        bool found;
        if (counter >= 1)
        {
            Console.Write("Enter the text to search: ");
            search = Console.ReadLine();
            found = false;
            string newValue5;

            for (int i = 0; i < counter; i++)
            {
                if (tasks[i].description.IndexOf(search) >= 0
                    || tasks[i].category.IndexOf(search) >= 0)
                {
                    if (tasks[i].description.Length > 50)
                        newValue5 = tasks[i].description.Substring(0, 50);
                    else
                        newValue5 = tasks[i].description;

                    found = true;
                    Console.WriteLine("{0}: {1}/{2}/{3} - {4}",
                        i + 1, tasks[i].date.day, tasks[i].date.month,
                        tasks[i].date.year, newValue5);
                }
            }
            if (!found)
                Console.WriteLine("Not found.");
        }
        else
            Console.WriteLine("Database empty.");
    }

    public static void Update()
    {
        string newValue;
        if (counter >= 1)
        {
            Console.Write("Enter the number of the task to update: ");
            int update = Convert.ToInt32(Console.ReadLine()) - 1;
            if ((update >= 0) && (update < counter))
            {
                Console.Write("Description ({0}): ",
                    tasks[update].description);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update].description = newValue;

                Console.WriteLine("Level ({0}): ",
                    tasks[update].level);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update].level = Convert.ToByte(newValue);

                Console.WriteLine("Category ({0}): ",
                    tasks[update].category);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update].category = newValue;

                Console.WriteLine("Year ({0}): ",
                    tasks[update].date.year);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update].date.year = Convert.ToUInt16(newValue);

                Console.WriteLine("Month ({0}): ",
                    tasks[update].date.month);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update].date.month = Convert.ToByte(newValue);

                Console.WriteLine("Day ({0}): ",
                    tasks[update].date.day);
                newValue = Console.ReadLine();
                if (newValue != "")
                    tasks[update - 1].date.day = Convert.ToByte(newValue);
            }
            else
                Console.WriteLine("Wrong number entered.");
        }
        else
            Console.WriteLine("Database empty.");
    }

    public static void Delete()
    {
        if (counter >= 1)
        {
            Console.Write("Enter the first number of data to delete: ");
            int delete = Convert.ToInt32(Console.ReadLine()) - 1;
            Console.Write("Enter the second number of data to delete: ");
            int delete2 = Convert.ToInt32(Console.ReadLine()) - 1;

            for (int pos = delete; pos <= delete2; pos++)
            {
                for (int i = delete2; i < counter; i++)
                    tasks[i] = tasks[i + 1];
                counter--;
            }
        }
        else
            Console.WriteLine("Database empty.");
    }

    public static void Sort()
    {
        for (int i = 0; i < counter - 1; i++)
        {
            string firstDate = "" + tasks[i].date.year +
                tasks[i].date.month.ToString("00") +
                tasks[i].date.day.ToString("00") +
                tasks[i].description;
            for (int j = i + 1; j < counter; j++)
            {
                string secondDate = "" + tasks[j].date.year +
                    tasks[j].date.month.ToString("00") +
                    tasks[j].date.day.ToString("00") +
                    tasks[j].description;

                if (firstDate.CompareTo(secondDate) > 0)
                {
                    TaskType aux = tasks[i];
                    tasks[i] = tasks[j];
                    tasks[j] = aux;
                }
            }
        }
    }

    public static void FindDuplicates()
    {
        for (int i = 0; i < counter - 1; i++)
        {
            for (int j = i + 1; j < counter; j++)
            {
                if (tasks[i].description == tasks[j].description)
                {
                    Console.WriteLine("{0} - {1}/{2}/{3}",
                        tasks[i].description, tasks[i].date.day,
                        tasks[i].date.month, tasks[i].date.year);
                    Console.WriteLine("{0} - {1}/{2}/{3}",
                        tasks[j].description, tasks[j].date.day,
                        tasks[j].date.month, tasks[j].date.year);
                }
            }
        }
    }

    public static void Main()
    {
        char option;

        do
        {
            Console.WriteLine();
            Console.WriteLine("Tasks database");
            Console.WriteLine();
            Console.WriteLine("1- Add a new task.");
            Console.WriteLine("2- Show the tasks between two certain dates.");
            Console.WriteLine("3- Find tasks that contain a certain text.");
            Console.WriteLine("4- Update a record.");
            Console.WriteLine("5- Delete some data, between two positions indicated.");
            Console.WriteLine("6- Sort the data alphabetically by date.");
            Console.WriteLine("7- Find Duplicates.");
            Console.WriteLine("Q- Quit.");
            Console.WriteLine("Enter an option:");
            option = Convert.ToChar(Console.ReadLine().ToUpper());

            switch (option)
            {
                case '1': //Add a new task
                    Add();
                    break;

                case '2': //Show the tasks between two certain dates
                    Show();
                    break;

                case '3': //Find tasks that contain a certain text
                    Find();
                    break;

                case '4': //Update a record
                    Update();
                    break;

                case '5': //Delete some data, between two positions indicated by the user
                    Delete();
                    break;

                case '6': //Sort the data alphabetically on date + description
                    Sort();
                    break;

                case '7': //Find Duplicates
                    FindDuplicates();
                    break;

                case 'Q': //Quit
                    Console.WriteLine("Quitting...");
                    break;

                default:
                    Console.WriteLine("You entered a wrong option. Please re-enter it.");
                    break;
            }
        }
        while (option != 'Q');
    }
}

Juan A. Ripoll - Systems Tutorials and Programming Courses ©  All rights reserved.  Legal Conditions.