In ASP, Bit Operator Left shift and Right shift
Does anyone know left shift and right shift operator sample's? I'm new in ASP.开发者_如何学运维 I found Bit operators such as AND,OR,NOT only..
For vbscript, left shift is accomplished by multiplication (i.e., var * 2 left shifts one position, var * 4 lefts shifts two positions, etc.) and right shift is accomplished by division (i.e., var \ 16 right shifts four positions).
There are no direct methods for left and right shift in vbscript, but as this is a simple move of each digit in a set of bits left or right, which can be done by dividing by binary 10 (integer 2), here are helper methods that do this
Function LeftShift(pValue, pShift)
Dim NewValue, PrevValue, i
PrevValue = pValue
For i = 1 to pShift
Select Case VarType(pValue)
Case vbLong
NewValue = (PrevValue And "&H3FFFFFFF") * 2
If PrevValue And "&H40000000" Then NewValue = NewValue Or "&H80000000"
NewValue = CLng(NewValue)
Case vbInteger
NewValue = (PrevValue And "&H3FFF") * 2
If PrevValue And "&H4000" Then NewValue = NewValue Or "&H8000"
NewValue = CInt("&H"+ Hex(NewValue))
Case vbByte
NewValue = CByte((PrevValue And "&H7F") * 2)
Case Else: Err.Raise 13 ' Not a supported type
End Select
PrevValue = NewValue
Next
LeftShift = NewVAlue
End Function
Function RightShift(pValue, pShift)
Dim NewValue, PrevValue, i
PrevValue = pValue
For i = 1 to pShift
Select Case VarType(pValue)
Case vbLong
NewValue = Int((PrevValue And "&H7FFFFFFF") / 2)
If PrevValue And "&H80000000" Then NewValue = NewValue Or "&H40000000"
NewValue = CLng(NewValue)
Case vbInteger
NewValue = Int((PrevValue And "&H7FFF") / 2)
If PrevValue And "&H8000" Then NewValue = NewValue Or "&H4000"
NewValue = CInt(NewValue)
Case vbByte
NewValue = CByte(PrevValue / 2)
Case Else: Err.Raise 13 ' Not a supported type
End Select
PrevValue = NewValue
Next
RightShift = PrevValue
End Function
For more, see http://chris.wastedhalo.com/2014/05/more-binarybitwise-functions-for-vbscript/
http://www.blackwasp.co.uk/CSharpShiftOperators.aspx
That's C# but the same operators work in recent versions of VB.Net.
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