excel vba are bits set in byte code example

Example 1: excel vba long to bits

Function LongToBits$(ByVal n&)
    Dim i&
    LongToBits = "00000000000000000000000000000000"
    If n And &H80000000 Then
        Mid$(LongToBits, 1, 1) = "1"
        n = n And Not &H80000000
    End If
    For i = 32 To 2 Step -1
        If n And 1 Then Mid$(LongToBits, i, 1) = "1"
        n = n \ 2
    Next
End Function

'------------------------------------------------------------------------------

MsgBox ByteToBits(0)			'<--displays: 00000000000000000000000000000000
MsgBox LongToBits(293781237)	'<--displays: 00010001100000101011111011110101
MsgBox ByteToBits(-1)			'<--displays: 11111111111111111111111111111111

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

Example 4: vba bits to byte

'Extremely fast VBA function to convert a binary string to a Byte:

Function BitsToByte(bits$) As Byte
    Dim i&
    Static b() As Byte
    If LenB(bits) > 16 Then Exit Function
    If LenB(bits) = 16 Then
        b = bits
    Else
        b = String$(8 - Len(bits), "0") & bits
    End If
    For i = 0 To 14 Step 2
        BitsToByte = 2 * BitsToByte Or (b(i) Xor 48)
    Next
End Function


'Example:

MsgBox BitsToByte("00001100")		'<--displays: 12
MsgBox BitsToByte("10000001")		'<--displays: 129
'
'
'