1. VBA (continued) DSC340 Mike Pangburn

2. Consider a quite different example  You need to compute someone’s exact age.  The math is actually somewhat complicated and we don’t have time/energy/experience to figure it out, so we perform a Google search on VBA code and calculating someone’s age.  Here’s what I found…

3. VBA age calculator from WWW ‘ Determines time in Years (Y), Months (M), and Days (D) between Date1 and Date2 Dim Temp1 As Date Temp1 = DateSerial(Year(Date2), Month(Date1), Day(Date1)) Y = Year(Date2) - Year(Date1) + (Temp1 > Date2) M = Month(Date2) - Month(Date1) - (12 * (Temp1 > Date2)) D = Day(Date2) - Day(Date1) If D < 0 Then M = M - 1 D = Day(DateSerial(Year(Date2), Month(Date2) + 1, 0)) + D + 1 End If

4. Store Y, M, D info in an object  I’d like a “date object” to store the 3 date parts (Y, M, and D)  There is no such built-in object type (i.e., a “class”) in VBA  So, I can create one, which I decided to call timeInYMD

5. Using my new class  Assuming I have used the WWW code I found to calculate Y, M, and D, I want to create an object from my new class  Here is what that code would look like in VBA syntax Dim result As timeInYMD ‘ declares the new variable named result Set result = New timeInYMD ‘ sets the var. equal to a new timeInYMD object result.Years = Y result.Months = M result.Days = D

6. My complete Age() function Function Age(Date1 As Date, Date2 As Date) As timeInYMD Dim Y, M, D As Integer Dim Temp1 As Date ' Math/code found on WWW Google search Temp1 = DateSerial(Year(Date2), Month(Date1), Day(Date1)) Y = Year(Date2) - Year(Date1) + (Temp1 > Date2) M = Month(Date2) - Month(Date1) - (12 * (Temp1 > Date2)) D = Day(Date2) - Day(Date1) If D < 0 Then M = M - 1 D = Day(DateSerial(Year(Date2), Month(Date2) + 1, 0)) + D + 1 End If ' End of found code computing age in Y, M, D Dim result As timeInYMD Set result = New timeInYMD result.Years = Y result.Months = M result.Days = D Set Age = result End Function

7. How do we get the user’s DOB?  We could get the user’s DOB (date of birth) by having it typed into a worksheet cell  Let’s see how we can do it with a dialog box  Again, we can do a Google WWW search to find some example VBA code for an input box window. Here’s what I found: Dim DOB As Date DOB = InputBox ( Prompt :="Your DOB please", Title :="ENTER DOB", Default :="01/01/2001")

8. Once we have their DOB, call Age()  After the user types their DOB into the dialog box, we compute their age via our Age() function, which returns a timeInYMD object  So we can hold that result in our program using a timeInYMD object variable Dim yourAge As timeInYMD Set yourAge = Age(DOB, Date)

9. Report info to user in a MsgBox  This code will report the results back to the user Dim messageStart As String messageStart = "That would suggest you are " & yourAge.Years & " years, " & yourAge.Months & " months, and ” & yourAge.Days & " days old." MsgBox messageStart, vbInformation, "Age Calculator"

10. My complete subroutine Sub ProcessUserDOB() Dim DOB As Date DOB = InputBox(Prompt:="Your DOB please (e.g., 01/15/1988)", Title:="ENTER YOUR DOB", Default:="01/01/2001") Dim yourAge As timeInYMD Set yourAge = Age(DOB, Date) Dim messageStart As String messageStart = "That would suggest you are " & yourAge.Years & " years, " & yourAge.Months & " months, and ” & yourAge.Days & " days old.” MsgBox messageStart, vbInformation, "Age Calculator” End Sub

11. Let’s call another sub to give voting/drinking info.  Let’s write another sub()  We will call it at the bottom of the prior sub by adding the line: Call ReportDrinkingVotingStatus(yourAge)  This new sub will take the person’s age and determine:  Is the person of legal drinking age?  Is the person of legal voting age?

12. Figuring out the voting/drinking Qs  Is the age eligible for voting or drinking? Dim canDrink, canVote As Boolean If yourAge.Years >= 21 Then canDrink = True Else: canDrink = False End If If yourAge.Years >= 18 Then canVote = True Else: canVote = False End If

13. Report the results using a MsgBox If canDrink And canVote Then messageEnd = “Good news, that would mean you can drink and vote." Else: If canVote Then messageEnd = " You can't drink, but you can vote." Else: messageEnd = " Bummer, you can't drink or vote." End If MsgBox messageEnd, vbInformation, "Age Calculator"

14. The complete voting/drinking sub Sub ReportDrinkingVotingStatus(yourAge As timeInYMD) Dim messageEnd As String Dim canDrink, canVote As Boolean If yourAge.Years >= 21 Then canDrink = True Else: canDrink = False End If If yourAge.Years >= 18 Then canVote = True Else: canVote = False End If If canDrink And canVote Then messageEnd = " Good news, that would mean you can drink and vote." Else: If canVote Then messageEnd = " You can't drink, but you can vote." Else: messageEnd = " Bummer, you can't drink or vote." End If MsgBox messageEnd, vbInformation, "Age Calculator" End Sub