' Bit-String Calculator Demo Program
' Mr. Minich
' Purpose - to illustrate the code for a couple of bit-string flicking operations.
'               Only the AND and RSHIFT operations work in this program. Notice that
'               a combo box named cboOperation is used in this program. Always use the
'               prefix 'cbo' when naming combo boxes. To enter the user's options for
'               a combo box, type them into its List property.


Option Explicit

Private Sub cmdCalculate_Click()
    Dim J As Integer            ' loop variable
    Dim ZeroString As String    ' a string of zeros to be used when shifting a bit string
    
    If cboOperation = "AND" Then
    
        For J = 1 To Len(txtBitString1)
        
            lblAnswer = lblAnswer & (Val(Mid$(txtBitString1, J, 1)) And _
                Val(Mid$(txtBitString2, J, 1)))
                
        Next J
        
    End If              ' the And operator performs the same bit-wise logical
                        '    operation as AND in bit-string flicking.
                        '    Visual Basic also uses the bit-wise operators, NOT, OR,
                        '    and XOR. You can easily combine NOT and XOR to
                        '    perform the XNOR operation since XNOR is not defined
                        '    as an operator in Visual Basic. Or, you can use VB's Eqv
			'    operator which is equivalent to the XNOR operation but refer
			'    to this demo program for help.
    
    ' ******************
    ' Add If/Then statements for the other required logical operators here.
    ' ******************
    
    If cboOperation = "RSHIFT" Then
    
        For J = 1 To Val(txtAmount)           ' building a string of zeros of the
            ZeroString = ZeroString & "0"     '   necessary length for later concatenation
        Next J
        
        lblAnswer = ZeroString & Left$(txtBitString1, Len(txtBitString1) - Val(txtAmount))
    End If
    
    ' ******************
    ' Add If/Then statements for the other required shift and circulate operators here.
    ' ******************
End Sub

Private Sub cmdClear_Click()
    lblAnswer = ""              ' clearing the text boxes and labels
    txtBitString1 = ""
    txtBitString2 = ""
    txtAmount = 0
End Sub

Private Sub CmdExit_Click()
    End                         ' exiting the program
End Sub