excelvba swap byte order code example

Example: excel vba swap byte order

'Extremely fast VBA function to convert a LONG value from Little-Endian 
'to Big-Endian byte order representation, and vice versa:

Function ConvertEndianness&(ByVal n&)
    ConvertEndianness = (((n And -16777216) \ 16777216) And 255&) Or _
                        ((n And 16711680) \ 256&) Or ((n And 65280) * 256&) Or ((n And 127&) * 16777216)
    If (n And 128&) Then ConvertEndianness = ConvertEndianness Or &H80000000
End Function
  
'------------------------------------------------------------------------------------------------
  
MsgBox ConvertEndianness(127)			'<--displays:   2130706432
MsgBox ConvertEndianness(2130706432)	'<--displays:   127


'NB: This function converts byte order:  &h12345678 --> &h78563412
'                                        &h78563412 --> &h12345678


'Reference:
    https://en.wikipedia.org/wiki/Endianness