Dynamic Arrays (continued)

Class Exercise: Class List

We will make a program that allows the user to display and search several different class lists.

  1. Begin by designing the form.
  2. Use the names lstStudents, lblCount, cmdFirstGrade, cmdSecondGrade, txtFind, cmdFind, cmdDone for the controls on the form.
  3. Add code to cmdDone.
  4. Add a global array variable named strStudents().
  5. Add code to cmdFirstGrade and cmdSecondGrade to redimension the array and set the names of the students. Finally, call a subroutine named DisplayList.
  6. Create a subroutine named DisplayList that uses a For…Next loop to display the names of the students in the array.
  7. Add code to cmdFind that searches the currently displayed class list for any whole or partial matches (not case sensitive).

Class List Code 
    ' global variables
    Dim strStudents() As String

Private Sub cmdDone_Click()
‘ end program
Unload frmMain
End Sub

Private Sub cmdFirstGrade_Click()
‘ resize array
ReDim strStudents(1 To 7)
‘ save student names
strStudents(1) = “Doc”
strStudents(2) = “Grumpy”
strStudents(3) = “Sneezy”
strStudents(4) = “Happy”
strStudents(5) = “Sleepy”
strStudents(6) = “Bashful”
strStudents(7) = “Dopey”
‘ display
Call DisplayList
End Sub

Private Sub cmdSecondGrade_Click()
‘ resize array
ReDim strStudents(1 To 4)
‘ save student names
strStudents(1) = “John”
strStudents(2) = “Paul”
strStudents(3) = “George”
strStudents(4) = “Ringo”
‘ display
Call DisplayList
End Sub

Sub DisplayList()
‘ ********************************************************
‘ ** Display student list
‘ ********************************************************

‘ dimension
Dim intCount As Integer
‘ clear list box
lstStudents.Clear
‘ display items
For intCount = 1 To UBound(strStudents)
Call lstStudents.AddItem(strStudents(intCount))
Next intCount
‘ display count
lblCount.Caption = CStr(lstStudents.ListCount) & ” students”
End Sub

Private Sub cmdFind_Click()
‘ dimension
Dim strFind As String
Dim intSearchPos As Integer
Dim blnFound As Boolean
‘ initialize
strFind = txtFind.Text
intSearchPos = 1
‘ linear search loop
Do Until intSearchPos > UBound(strStudents) Or blnFound
If InStr(UCase(strStudents(intSearchPos)), UCase(strFind)) Then
‘ found it!
Call MsgBox(“Found student: ” & strStudents(intSearchPos), _
vbInformation)
blnFound = True
End If
‘ next student
intSearchPos = intSearchPos + 1
Loop
End Sub