Question

my byte array has these first 8 values,
0 0 12 12
0 0 127 224

However when I read the bitarray after conversion,
it has,

0000,0000 0000,0000 0011,0000 0011,0000
0000,0000 0000,0000 1111,1110 0000,0111

I have no idea why bitarray have these values…

ANybody knows why this is happening?

Code used for the conversion is;

byte[] bytes = System.IO.File.ReadAllBytes(args[0]);

BitArray bits = new BitArray(bytes);

Answer 1

All the bits need to be read from right to left in order to make sense.

0000,0000
0000,0000
0011,0000 –> 00001100 = 12
0011,0000
0000,0000
0000,0000
1111,1110 –> 01111111 = 127
0000,0111

That’s just the way the BitArray works.

http://msdn.microsoft.com/en-us/library/x1xda43a.aspx

The first byte in the array represents bits 0 through 7,
the second byte represents bits 8 through 15, and so on.
The Least Significant Bit of each byte represents the lowest index value:
"bytes [0] & 1" represents bit 0,
"bytes [0] & 2" represents bit 1,
"bytes [0] & 4" represents bit 2,
and so on.

So the least significant bit of the first byte in the array is bit 0 in the bit array and the second least significant bit of the first byte in the array is bit 1 in the bit array.

I have no idea why they did it that way.