What are the Integer values of Boolean False and True in VB6?

Question

I\'m working with a bit of old VB6 code that goes thus...

Dim STATUS As Integer

STATUS = -1

If (Not STATUS) Then
\' do something
Else
\' do something else
         


        

Answer 1

Not really an answer, but just poking about, I typed this into the immediate window, with these results:

For x = -5 To 5 : ? x, CBool(x), ( x = True ), ( x = False ) : Next x
-5            True          False         False
-4            True          False         False
-3            True          False         False
-2            True          False         False
-1            True          True          False
 0            False         False         True
 1            True          False         False
 2            True          False         False
 3            True          False         False
 4            True          False         False
 5            True          False         False

(I tested more values, but only -1 and 0 had anything "interesting" going on. The rest were all True/False/False.) So, empirically, I'd say that the comparison is being done arithmetically unless you cast with CBool. Why? I can't really say...

Answer 2

In VB 6, True has a numeric value of -1. False has a numeric value of 0.

The reason for this is because the Boolean data type is stored as a 16-bit signed integer. Therefore,
-1 evaluates to 16 1s in binary (1111111111111111). False is 16 0s (0000000000000000). This produces the relationship that has held throughout the evolution of BASIC: True = Not False.

Answer 3

True is stored as -1 and false as 0. Any non-zero value is considered as true.

To see why it is so please check - http://www.vbforums.com/showthread.php?t=405047