Access VBA Logical Operators

Same as VB. Access VBA logical operators:

Access VBA never short circuits. Given the expression this or that as well as this and that, if this evaluates to false, then that is still executed.

Using the Logical Not Operator

You can use the not operator in many contexts. One of my favorite uses for it is to toggle boolean properities with a single line of code:

BooleanProperty = Not BooleanProperty

MS Access 2003 Working Demo

The following demo uses the not operator to toggle the visible property of a Image object from a button.

1. Create a new form and place a button and a Image on it. Add a picture to the Image with the Picture property.
     
   
    
2. Edit the Click event of the button and alter it as follows below. Select the button and edit the On Click event on the Event tab of the Properities explorer. Your Image object should be named Image1, but if it's not, use the correct object name.
    
   Private Sub Command1_Click()
       Image1.Visible = Not Image1.Visible
   End Sub
    
3. Run the form and test. Select View | Form View and click the button. You'll notice the picture toggles between visible and not visible with a single line of code.

Access VBA Short Circuting Example:

In the following example, if Access VBA supported short circuting, the That function would never execute.

Function This()
    MsgBox ("The This function executed.")
    This = False
End Function

Function That()
    MsgBox ("The That function executed!")
    That = True
End Function

Private Sub Command0_Click()
    'Notice both the This and That functions execute
    'even though the This Function returned False.
    If This And That Then
        MsgBox ("hi")
    End If
End Sub