Exercise
Exercise tasks
Objetive
Write a Visual Basic (VB.Net) 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).
Code
Imports System
Public Class exercis95
Structure DateType
Public year As UShort
Public month As Byte
Public day As Byte
End Structure
Structure TaskType
Public date As DateType
Public description As String
Public level As Byte
Public category As String
End Structure
Public Shared Sub Main()
Dim capacity As Integer = 2000
Dim tasks As TaskType() = New TaskType(capacity - 1) {}
Dim [option] As Char
Dim counter As Integer = 0
Dim search, newValue As String
Dim found As Boolean
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())
Select Case [option]
Case "1"c
If counter < capacity Then
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 OrElse tasks(counter).date.day > 31 Then Console.WriteLine("Not a valid day!")
Loop While tasks(counter).date.day < 1 OrElse 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 OrElse tasks(counter).date.month > 12 Then Console.WriteLine("Not a valid month!")
Loop While tasks(counter).date.month < 1 OrElse 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 OrElse tasks(counter).date.year > 3000 Then Console.WriteLine("Not a valid year!")
Loop While tasks(counter).date.year < 1000 OrElse tasks(counter).date.year > 3000
counter += 1
Else
Console.WriteLine("Database full.")
End If
Case "2"c
If counter >= 1 Then
Dim startDay, startMonth As Byte
Dim startYear As UShort
Dim endDay, endMonth As Byte
Dim endYear As UShort
Console.WriteLine("Starting day: ")
Dim number As String = Console.ReadLine()
If number = "" Then
startDay = Convert.ToByte(DateTime.Now.Day)
Else
startDay = Convert.ToByte(number)
End If
Console.WriteLine("Starting month: ")
number = Console.ReadLine()
If number = "" Then
startMonth = Convert.ToByte(DateTime.Now.Month)
Else
startMonth = Convert.ToByte(number)
End If
Console.WriteLine("Starting year: ")
number = Console.ReadLine()
If number = "" Then
startYear = Convert.ToUInt16(DateTime.Now.Year)
Else
startYear = Convert.ToUInt16(number)
End If
Console.WriteLine("Final day: ")
number = Console.ReadLine()
If number = "" Then
endDay = Convert.ToByte(DateTime.Now.Day)
Else
endDay = Convert.ToByte(number)
End If
Console.WriteLine("Final month: ")
number = Console.ReadLine()
If number = "" Then
endMonth = Convert.ToByte(DateTime.Now.Month)
Else
endMonth = Convert.ToByte(number)
End If
Console.WriteLine("Final year: ")
number = Console.ReadLine()
If number = "" Then
endYear = Convert.ToUInt16(DateTime.Now.Year)
Else
endYear = Convert.ToUInt16(number)
End If
Dim startDate As String = "" & startYear & startMonth.ToString("00") & startDay.ToString("00")
Dim endDate As String = "" & endYear & endMonth.ToString("00") & endDay.ToString("00")
For i As Integer = 0 To counter - 1
Dim currentDate As String = "" & tasks(i).date.year & tasks(i).date.month.ToString("00") & tasks(i).date.day.ToString("00")
If currentDate.CompareTo(startDate) >= 0 AndAlso currentDate.CompareTo(endDate) <= 0 Then
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)
End If
Next
Else
Console.WriteLine("Database empty.")
End If
Case "3"c
If counter >= 1 Then
Console.Write("Enter the text to search: ")
search = Console.ReadLine()
found = False
Dim newValue5 As String
For i As Integer = 0 To counter - 1
If tasks(i).description.IndexOf(search) >= 0 OrElse tasks(i).category.IndexOf(search) >= 0 Then
If tasks(i).description.Length > 50 Then
newValue5 = tasks(i).description.Substring(0, 50)
Else
newValue5 = tasks(i).description
End If
found = True
Console.WriteLine("{0}: {1}/{2}/{3} - {4}", i + 1, tasks(i).date.day, tasks(i).date.month, tasks(i).date.year, newValue5)
End If
Next
If Not found Then Console.WriteLine("Not found.")
Else
Console.WriteLine("Database empty.")
End If
Case "4"c
If counter >= 1 Then
Console.Write("Enter the number of the task to update: ")
Dim update As Integer = Convert.ToInt32(Console.ReadLine()) - 1
If (update >= 0) AndAlso (update < counter) Then
Console.Write("Description ({0}): ", tasks(update).description)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).description = newValue
Console.WriteLine("Level ({0}): ", tasks(update).level)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).level = Convert.ToByte(newValue)
Console.WriteLine("Category ({0}): ", tasks(update).category)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).category = newValue
Console.WriteLine("Year ({0}): ", tasks(update).date.year)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).date.year = Convert.ToUInt16(newValue)
Console.WriteLine("Month ({0}): ", tasks(update).date.month)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).date.month = Convert.ToByte(newValue)
Console.WriteLine("Day ({0}): ", tasks(update).date.day)
newValue = Console.ReadLine()
If newValue <> "" Then tasks(update).date.day = Convert.ToByte(newValue)
Else
Console.WriteLine("Wrong number entered.")
End If
Else
Console.WriteLine("Database empty.")
End If
Case "5"c
If counter >= 1 Then
Console.Write("Enter the first number of data to delete: ")
Dim delete As Integer = Convert.ToInt32(Console.ReadLine()) - 1
Console.Write("Enter the second number of data to delete: ")
Dim delete2 As Integer = Convert.ToInt32(Console.ReadLine()) - 1
For pos As Integer = delete To delete2
For i As Integer = delete To counter - 1
tasks(i) = tasks(i + 1)
Next
counter -= 1
Next
Else
Console.WriteLine("Database empty.")
End If
Case "6"c
For i As Integer = 0 To counter - 1 - 1
Dim firstDate As String = "" & tasks(i).date.year & tasks(i).date.month.ToString("00") & tasks(i).date.day.ToString("00") & tasks(i).description
For j As Integer = i + 1 To counter - 1
Dim secondDate As String = "" & tasks(j).date.year & tasks(j).date.month.ToString("00") & tasks(j).date.day.ToString("00") & tasks(j).description
If firstDate.CompareTo(secondDate) > 0 Then
Dim aux As TaskType = tasks(i)
tasks(i) = tasks(j)
tasks(j) = aux
End If
Next
Next
Case "7"c
For i As Integer = 0 To counter - 1 - 1
For j As Integer = i + 1 To counter - 1
If tasks(i).description = tasks(j).description Then
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)
End If
Next
Next
Case "Q"c
Console.WriteLine("Quitting...")
Case Else
Console.WriteLine("You entered a wrong option. Please re-enter it.")
End Select
Loop While [option] <> "Q"c
End Sub
End Class