vba test if specific bits are set in 32-bit long integer code example
Example 1: excel vba are bits set in integer
'Fast VBA function to test if specific bits are set
'within a 16-bit Integer. If ALL specified bits are set then
'this function returns True. If ANY of the specified bits are
'not set then this function returns False.
'Bits are numbered from 0 to 15, so the first (least significant) bit
'is bit 0.
'Note: bits can be specified in any order.
'Note: any number of bits can be specified in one call.
Function IntegerBitsAreSet(theInteger%, ParamArray bits()) As Boolean
Static i&, b%()
If UBound(bits) = -1 Then Exit Function
If (Not Not b) = 0 Then
ReDim b(0 To 14)
For i = 0 To 14
b(i) = 2 ^ i
Next
End If
For i = 0 To UBound(bits)
If bits(i) < 0 Then Exit Function
If bits(i) > 14 Then Exit Function
If (theInteger And b(Int(bits(i)))) = 0 Then Exit Function
Next
IntegerBitsAreSet = True
End Function
'----------------------------------------------------------------------------------------
MsgBox IntegerBitsAreSet(255, 7) '<--displays: True 255 = 00000000 11111111
MsgBox IntegerBitsAreSet(230, 0) '<--displays: False 230 = 00000000 11100110
MsgBox IntegerBitsAreSet(85, 0, 2, 6, 4) '<--displays: True 85 = 00000000 01010101
MsgBox IntegerBitsAreSet(85, 0, 2, 5, 4) '<--displays: False 85 = 00000000 01010101
MsgBox IntegerBitsAreSet(485, 2, 7, 5) '<--displays: True 485 = 00000001 11100101
MsgBox IntegerBitsAreSet(24585, 14, 13, 3) '<--displays: True 24585 = 01100000 00001001
'
'
'
Example 2: excel vba are bits set in byte
'Fast VBA function to test if specific bits are set
'within a Byte. If ALL specified bits are set then this function
'returns True. If ANY of the specified bits are not set then
'this function returns False.
'Bits are numbered from 0 to 7, so the first (least significant) bit
'is bit 0.
'Note: bits can be specified in any order.
Function ByteBitsAreSet(theByte As Byte, ParamArray bits()) As Boolean
Static i&, b() As Byte
If UBound(bits) = -1 Then Exit Function
If (Not Not b) = 0 Then
ReDim b(0 To 7)
For i = 0 To 7
b(i) = 2 ^ i
Next
End If
For i = 0 To UBound(bits)
If bits(i) < 0 Then Exit Function
If bits(i) > 7 Then Exit Function
If (theByte And b(Int(bits(i)))) = 0 Then Exit Function
Next
ByteBitsAreSet = True
End Function
'--------------------------------------------------------------------------
MsgBox ByteBitsAreSet(255, 7) '<--displays: True 255 = 11111111
MsgBox ByteBitsAreSet(230, 0) '<--displays: False 230 = 11100110
MsgBox ByteBitsAreSet(85, 0, 2, 6, 4) '<--displays: True 85 = 01010101
MsgBox ByteBitsAreSet(85, 0, 2, 5, 4) '<--displays: False 85 = 01010101
'
'
'
Example 3: excel vba is bit set long
'Extremely fast VBA function to test if a specified bit is set
'within a 32-bit Long integer.
'Bits are numbered from 0 to 31, so the first (least significant) bit
'is bit 0.
'Note: we do not inspect bit 31, the sign bit.
'Note: any number of bits can be specified in one call.
Function LongBitIsSet(theLong&, bit As Byte) As Boolean
Static i&, b&()
If (Not Not b) = 0 Then
ReDim b(0 To 30)
For i = 0 To 30
b(i) = 2 ^ i
Next
End If
If bit < 31 Then LongBitIsSet = theLong And b(bit)
End Function
'------------------------------------------------------------------
MsgBox LongBitIsSet(255, 7) '<--displays: True
MsgBox LongBitIsSet(230, 0) '<--displays: False
MsgBox LongBitIsSet(16384, 14) '<--displays: True
MsgBox LongBitIsSet(-16383, 0) '<--displays: True
MsgBox LongBitIsSet(&H7FFFFFFF, 0) '<--displays: True