posted 15 years ago
As an int, 129 has the following bit representation
00000000000000000000000010000001
When you cast to a byte, you only have the last 8 bits.
So you have the byte
10000001
Because the first bit is a 1, this is a negative number.
To find out what number it is the negative of, flip all the bits and add 1
You get
01111111
So the number is -127.