Practice Exercises C# Sharp - Learn to program with performing exercises C# Sharp

Practice Exercises C# Sharp

Learn to program with performing exercises C# Sharp


Exercise tasks - Practice Exercises C# Sharp


Lesson 4:

Structures and Strings


Exercise 4.24:

Exercise tasks


Objetive:

Create a C# program that can store up to 2000 "to-do tasks". For each task, it must keep the following data:

• Date (a set of 3 data: day, month and year)
• Description of task
• Level of importance (1 to 10)
• Category

The program should allow the user the following operations:

1 - Add a new task (the date must "seem correct": day 1 to 31, month 1 to 12, year between 1000 and 3000).

2 - Show the tasks between two certain dates (day, month and year). If the user presses Enter without specifying date, it will be taken as "today". It must display the number of each record, the date (DD/ MM/YYYY), description, category and importance, all in the same line, separated with hyphens.

3 - Find tasks that contain a certain text (in description or category, not case sensitive). It will display number, date and description (only 50 letters, in case it was be longer). The user should be notified if none is found.

4 - Update a record (it will ask for the number, will display the previous value of each field and the user can press Enter not to modify any of the data). The user should be warned (but not asked again) if he enters an incorrect record number. It is not necessary to validate any of the fields.

5 - Delete some data, between two positions indicated by the user. The user should be warned (but not asked again) if he enters any incorrect record number. Each record to be deleted must be displayed, and the user must be asked for confirmation.

6 - Sort the data alphabetically by date and (if two dates are the same) by description.

7 - Find Duplicates: If two records have the same description, both will be displayed on-screen.

Q - Quit (end the application; as we do not store the information, it will be lost).

(Hint: you can know the current date using DateTime.Now.Day, DateTime.Now.Month and DateTime.Now.Year).


Source Code:


using System;
public class TasksDatabase
{
    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;
    }

    public static void Main()
    {
        int capacity = 2000;
        TaskType[] tasks = new TaskType[capacity];
        char option;
        int counter = 0;
        string search, newValue;
        bool found;

        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
                    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.");
                    break;

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

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

                case '4': //Update a record
                    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].date.day = Convert.ToByte(newValue);
                        }
                        else
                            Console.WriteLine("Wrong number entered.");
                    }
                    else
                        Console.WriteLine("Database empty.");
                    break;

                case '5': //Delete some data, between two positions indicated by the user
                    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 = delete; i < counter; i++)
                                tasks[i] = tasks[i + 1];
                            counter--;
                        }
                    }
                    else
                        Console.WriteLine("Database empty.");
                    break;

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

                case '7': //Find Duplicates
                    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);
                            }
                        }
                    }
                    break;

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

                default:
                    Console.WriteLine("You entered a wrong option. Please re-enter it.");
                    break;
            }
        }
        while (option != 'Q');
    }
}
Exercisey 4.24




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