WORKING WITH CONTROL ARRAY

A control array is a group of controls that share the same name type and the same event procedures. Adding controls with control arrays uses fewer resources than adding multiple control of same type at design time.

Form Description

Source Code:


Option Explicit
Dim Operand1 As Double, Operand2 As Double
Dim Operator As String
Dim ClearDisplay As Boolean

Private Sub ClearBttn_Click()
    Display.Caption = ""
End Sub

Private Sub Digits_Click(Index As Integer)
    If ClearDisplay Then
        Display.Caption = ""
        ClearDisplay = False
    End If
    Display.Caption = Display.Caption + Digits(Index).Caption
End Sub

Private Sub Div_Click()
    Operand1 = Val(Display.Caption)
    Operator = "/"
    Display.Caption = ""
End Sub

Private Sub DotBttn_Click()
    If ClearDisplay Then
        Display.Caption = ""
        ClearDisplay = False
    End If
    If InStr(Display.Caption, ".") Then
        Exit Sub
    Else
        Display.Caption = Display.Caption + "."
    End If
End Sub

Private Sub Equals_Click()
Dim result As Double

On Error GoTo ErrorHandler
    Operand2 = Val(Display.Caption)
    If Operator = "+" Then result = Operand1 + Operand2
    If Operator = "-" Then result = Operand1 - Operand2
    If Operator = "*" Then result = Operand1 * Operand2
    If Operator = "/" And Operand2 <> "0" Then result = Operand1 / Operand2
    Display.Caption = result
    ClearDisplay = True
    Exit Sub
ErrorHandler:
    Dim intMsg As Integer
    intMsg = MsgBox("The operation resulted in the following error" _
    & vbCrLf & Err.Description, vbOKCancel)
  
    Display.Caption = "ERROR " & intMsg
    ClearDisplay = True
End Sub

Private Sub Minus_Click()
    Operand1 = Val(Display.Caption)
    Operator = "-"
    Display.Caption = ""
End Sub

Private Sub Over_Click()
    If Val(Display.Caption) <> 0 Then Display.Caption = 1 / Val(Display.Caption)
End Sub

Private Sub Plus_Click()
    Operand1 = Val(Display.Caption)
    Operator = "+"
    Display.Caption = ""
End Sub

Private Sub PlusMinus_Click()
    Display.Caption = -Val(Display.Caption)
End Sub

Private Sub Times_Click()
    Operand1 = Val(Display.Caption)
    Operator = "*"
    Display.Caption = ""
End Sub