The Piecemeal Man (abmann) wrote,
The Piecemeal Man

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Our project for today was to design a program that calculates target heart rates for a user given their birthdate and heart rate. Now, we were supposed to learn to use SELECT CASE and If/Then statements are were not allowed use of any robust date functions (Like Cdate() or IsDate()). We had to break the user interface (UI) into three sections for Day, Month and Year rather than allow single entry in MM/DD/YYYY format.

Because we had three fields with which to deal, I had to write this nutty bit of code to validate for correct Day/Month combos, accept both YY and YYYY format and check for leap years.

'validate year data
 sTemp = Val(txtYear.Text)  'store year data in temporary string
    If sTemp <= 0 Then
      Call MsgBox("Please enter Year as a number.", , "In the zone - Year")
      txtYear.BackColor = &H8080FF
      Exit Sub
    ElseIf IsNumeric(sTemp) Then
      If Len(sTemp) = 4 Then
        iYear = sTemp
      ElseIf Len(sTemp) = 2 Then
          If Val(sTemp) < 30 Then
            iYear = 20 & sTemp
            iYear = 19 & sTemp 'the previous was a ridiculously involved validation of the date, so both YY and YYYY formats work
          End If
      End If
    End If

'validate month data
  iMonth = Val(txtMonth.Text)  'store Month as numeric data
    If iMonth < 1 Or iMonth > 12 Then  'validate Month value for numeric data between 1 and 12
      Call MsgBox("Please enter Month as a number between 1 and 12.", , "In the zone - Month")
      txtMonth.BackColor = &H8080FF 'highlight field to fix
      Exit Sub
    End If

'set var that will determine valid day/month combos
  Select Case iMonth
    Case 4, 6, 9, 11
      iValidDay = 30
    Case 1, 3, 5, 7, 8, 10, 12
      iValidDay = 31
    Case 2 And iYear Mod 4 = 0 And iYear Mod 100 <> 0
      iValidDay = 29
    Case 2 And iYear Mod 4 <> 0
      iValidDay = 28
    End Select
'Validate & store day
  iDay = Val(txtDay.Text)  'store day as numeric data
   If iDay < 1 Or iDay > iValidDay Then
    Call MsgBox("Please enter Day as a number between 1 and " & iValidDay & ".", , "In the zone - Day")
    txtDay.BackColor = &H8080FF 'highlight incorrect field
    txtDay.SetFocus 'change cursor focus
    Exit Sub
  End If

'Calculate user age
  If iDay <= Day(Date) And iMonth <= Month(Date) Then
    iAge = Year(Date) - iYear 'calculate age
    iAge = Year(Date) - iYear - 1
  End If ' display age (used to test age formula)

End Sub

Now, it works. I'm willing to bet it's really clunky given that this is my second day coding in VB6.

Were we allowed to use the nifty date functions, the entire code above would have been as follows.
If IsDate(txtBirthDate.Text) Then 'validate if data entered is a real date
  iBirthdate = txtBirthDate 'store Birthdate in iBirthDate
  Call MsgBox("Please enter birthdate in Month Day, YYYY format.",,"Target Heart Rate - Date error") 'pop an error if date is invalid
End If

iBirthDateConverted = CDate(iBirthDate) 'convert data to date expression.. to be safe...

Not sure if that's exactly right, suffice that the code would be 10% as long as it is.

Still having fun in class though.
Tags: coding, vb, work
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