Can you interpret this Code ?

[JohnBates]

Hello everyone - It is obvious to me that the code below can change the value of iSelectedSpur to (2 to the power of isorttype). What I DONT understand is the use of OR


WHICH value gets assigned... is it always the HIGHER value?

Thanks for any help. John


If isorttype <> 0 Then


********* This is the statement I don't understand *******

iSelectedSpur = iSelectedSpur Or 2 ^ isorttype


End If

 

[MarkSweetland]

The value assigned to iSelectedSpur is a binary combination of the two values; iSelectedSpur Or'd with the value in isorttype. If either bit in either number is a one (set) then the result of that comparision is a one. If both are zero, the result is a zero. For example if isorttype = 1 and iSelectedSpur value = 9:

    original iSelectedSpur value = 9   1001
                           2 ^ 1 = 2   0010
                                       ----
  iSelectedSpur Or 2 ^ isorttype = 11  1011

Here's the AND operation where both bits must be set for a resultant 1:

    original iSelectedSpur value = 9   1001
                           2 ^ 1 = 2   0010
                                       ----
 iSelectedSpur AND 2 ^ isorttype = 0   0000

Mark

 

[chiph]

John &amp; Mark -

Be advised in the next version of VB (VB.NET), &quot;Or&quot; will always do logical comparisons. There will be a new operator called &quot;BitOr&quot; that will do binary operations on whole numbers.

So, if you want to check if either variable contains non-zero values, you'd do:
[tt]
c = a or b
[/tt]
and c will contain a 1 or 0, depending on the boolean logic of a or b being non-zero.

If you want to do a binary OR operation (like Mark did in his excellent example), you'd have to do this:
[tt]
c = a BitOr b
[/tt]

Chip H.

 

[edderic]

Or Round Numbers

Function Round(nValue As Double, nDigits As Integer) As Double
Round = Int(nValue * (10 ^ nDigits) + 0.5) / (10 ^ nDigits)
End Function

Private Sub Form_Load()
'Replace '19.8455' with the number you want to round, replace '2' with the number of
'digits after the point that the rounded numbr will have.
MsgBox Round(19.8455, 2)
End Sub

Eric De Decker
vbg.be@vbgroup.nl

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