date validation

im trying to get the user of my program to enter their date of birth ad for the program to return how old they are in years, months and days (you are 10 years, 3 months and 23 days old) type thing and if its their birthday, to return an appropriate message.

atm ive got a textbox for the days, a combo box for the month and another textbox for the year. i guess the real question is how do i use these to do the above. im very new to programming and this is my first project outside of tutorials ive done so please explain everything as clearly as you can.

(please if you could give me little bits of code to help PLEASE:confused:)

thanks in advance

Try this snippet :)

Code:

---

Module Module1

    Enum DateTypes
        Month = 0
        Day = 1
        Year = 2
    End Enum

    Sub Main()
        Dim DateNow(2), BirthDate(2), DaysOld, MonthsOld, YearsOld As Int32
        Dim sArr() As String = DateString.Split("-")

        For i As Int32 = 0 To 2
            DateNow(i) = sArr(i)
        Next

        Console.Write("Enter birthdate(XX-XX-XXXX) : ")
        sArr = Console.ReadLine.Split("-")

        For i As Int32 = 0 To 2
            BirthDate(i) = sArr(i)
        Next

        YearsOld = DateNow(DateTypes.Year) - BirthDate(DateTypes.Year)
        MonthsOld = DateNow(DateTypes.Month) - BirthDate(DateTypes.Month)
        DaysOld = DateNow(DateTypes.Day) - BirthDate(DateTypes.Day)

        If (DaysOld < 0) Then
            DaysOld = DaysInMonth(DateNow(DateTypes.Month)) + DaysOld
            MonthsOld -= 1
        End If

        If (MonthsOld < 0) Then
            MonthsOld = 12 + MonthsOld
            YearsOld -= 1
        End If

        Console.WriteLine("You are " & YearsOld & " years, " & MonthsOld & " months, and " & DaysOld & " days old.")
        Console.ReadKey()
    End Sub

    Function DaysInMonth(ByVal MonthID As Int32) As Int32
        Dim MonthArray() As Int32 = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
        Return MonthArray(MonthID - 1)
    End Function
End Module

---

EDIT
Sorry about the clear explanation missing, but I'm running late already :)

Since you are using textboxes, It's highly recommended you validate the values inside the textbox before you even attempt forming a date. This is so that if a user inputs irrational data (not a number between 1 and 31, for instance,) you can block execution and make the user fix their input.

Code:

---

Dim intDay as Integer

If Not Integer.TryParse(TextDay.Text, intDay) Then
    Messagebox.Show("The day you have entered is invalid! Please fix it!")   
    Return
End If

'intDay will now contain a number

If IntDay < 1 Or IntDay > DateTime.DaysInMonth(SelectedYear, SelectedMonth)
    Messagebox.Show("The day you have entered is invalid! Please fix it!")   
    Return
End if

---

This code is just a tip of the iceburg. Just copying and pasting will not make it work. Also, with some editing, this code will work for the year.

thanks for that but im sorry but i dont understand what most of it is doing, and it doesnt appear to be working

(my form has tbDays, cbMonths, tbYears and Button1)- where do i put these in, its probably that- my fault


sorry- this is for the big one at the top

Copy & Paste this into your code

Code:

---

Function GetTimeLived(ByVal Days As Int32, ByVal Months As Int32, ByVal Years As Int32) As String
        Dim DateNow(2), BirthDate(2), DaysOld, MonthsOld, YearsOld As Int32
        Dim sArr() As String = DateString.Split("-")

        For i As Int32 = 0 To 2
            DateNow(i) = sArr(i)
        Next

        BirthDate(0) = Months
        BirthDate(1) = Days
        BirthDate(2) = Years

        YearsOld = DateNow(DateTypes.Year) - BirthDate(DateTypes.Year)
        MonthsOld = DateNow(DateTypes.Month) - BirthDate(DateTypes.Month)
        DaysOld = DateNow(DateTypes.Day) - BirthDate(DateTypes.Day)

        If (DaysOld < 0) Then
            Dim MonthArray() As Int32 = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
            Dim DaysInMonth = MonthArray(DateNow(DateTypes.Month) - 1)
            DaysOld = DaysInMonth + DaysOld
            MonthsOld -= 1
        End If

        If (MonthsOld < 0) Then
            MonthsOld = 12 + MonthsOld
            YearsOld -= 1
        End If

        Return ("You are " & YearsOld & " years, " & MonthsOld & " months, and " & DaysOld & " days old.")
    End Function

---

And call it(for example) like this:

Code:

---

MsgBox(GetTimeLived(05, 07, 1988))

---

im not trying to be a pain but that doesnt seem to be working either- ive done exactly what you said, ive put the big bit at the top but outside the button click then inside the button click the message box call but changed it to instead of the numbers ive put my textboxes and the combobox

Quote:

---

Originally Posted by stuart1512

im not trying to be a pain but that doesnt seem to be working either- ive done exactly what you said, ive put the big bit at the top but outside the button click then inside the button click the message box call but changed it to instead of the numbers ive put my textboxes and the combobox

---

Exactly what part of it doesn't work? Are you getting errors? If so, what kind? What about posting your whole forms code?

this is the code ive got along with the errors at the bottom
(i have tbDays for the days, cbMonths for the months, tbYears for the Y
years and a button- Button1)

Code:

---

Public Class Form1

    Function
    Dim GetTimeLived(ByVal Days As Int32, ByVal Months As Int32, ByVal Years As Int32) As String
        Dim DateNow(2), BirthDate(2), DaysOld, MonthsOld, YearsOld As Int32
        Dim sArr() As String = DateString.Split("-")

        For i As Int32 = 0 To 2
            DateNow(i) = sArr(i)
        Next

        BirthDate(0) = Months
        BirthDate(1) = Days
        BirthDate(2) = Years

        YearsOld = DateNow(DateTypes.Year) - BirthDate(DateTypes.Year)
        MonthsOld = DateNow(DateTypes.Month) - BirthDate(DateTypes.Month)
        DaysOld = DateNow(DateTypes.Day) - BirthDate(DateTypes.Day)

        If (DaysOld < 0) Then
            Dim MonthArray() As Int32 = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
            Dim DaysInMonth = MonthArray(DateNow(DateTypes.Month) - 1)
            DaysOld = DaysInMonth + DaysOld
            MonthsOld -= 1
        End If

        If (MonthsOld < 0) Then
            MonthsOld = 12 + MonthsOld
            YearsOld -= 1
        End If

        Return ("You are " & YearsOld & " years, " & MonthsOld & " months, and " & DaysOld & " days old.")
    End Function


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim GetTimeLived As String
        MsgBox(GetTimeLived(tbDays, cbMonths, tbYears))
    End Sub
End Class

---

Error 1 Identifier expected. C:\Documents and Settings\Stuart\My Documents\Trinity\VBTutorials\TEST PROJECTS\DateValidation\DateValidation\Form1.vb 3 12 DateValidation

Error 2 Value of type 'System.Windows.Forms.TextBox' cannot be converted to 'Integer'. C:\Documents and Settings\Stuart\My Documents\Trinity\VBTutorials\TEST PROJECTS\DateValidation\DateValidation\Form1.vb 38 29 DateValidation

Error 3 Too many arguments to 'Public ReadOnly Default Property Chars(index As Integer) As Char'. C:\Documents and Settings\Stuart\My Documents\Trinity\VBTutorials\TEST PROJECTS\DateValidation\DateValidation\Form1.vb 38 37 DateValidation

Here's it fixed

Code:

---

Public Class Form1

    Function  GetTimeLived(ByVal Days As Int32, ByVal Months As Int32, ByVal Years As Int32) As String
        Dim DateNow(2), BirthDate(2), DaysOld, MonthsOld, YearsOld As Int32
        Dim sArr() As String = DateString.Split("-")

        For i As Int32 = 0 To 2
            DateNow(i) = sArr(i)
        Next

        BirthDate(0) = Months
        BirthDate(1) = Days
        BirthDate(2) = Years

        YearsOld = DateNow(DateTypes.Year) - BirthDate(DateTypes.Year)
        MonthsOld = DateNow(DateTypes.Month) - BirthDate(DateTypes.Month)
        DaysOld = DateNow(DateTypes.Day) - BirthDate(DateTypes.Day)

        If (DaysOld < 0) Then
            Dim MonthArray() As Int32 = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
            Dim DaysInMonth = MonthArray(DateNow(DateTypes.Month) - 1)
            DaysOld = DaysInMonth + DaysOld
            MonthsOld -= 1
        End If

        If (MonthsOld < 0) Then
            MonthsOld = 12 + MonthsOld
            YearsOld -= 1
        End If

        Return ("You are " & YearsOld & " years, " & MonthsOld & " months, and " & DaysOld & " days old.")
    End Function


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        MsgBox(GetTimeLived(tbDays.Text, cbMonths.Text, tbYears.Text))
    End Sub
End Class

---

You might want to check some basic tutorials about using functions and procedures, they're easy to learn and are the core of programming in general.

thanks for that but where the function is called in the message box, there is a run time error

-when casting from a number, the value must be less than infinity
-make sure the source type is convertible to the destination type
-get general help for this exception
-InnerException: make sure your method arguments in the right format
-InnerException: when convertign a string to DateTime, parse the string to take the date before putting each variable into the DateTime object
-get general help for the InnerException