why size of signed bytes is not equal to -128 to 128?

Question

range of bytes is -128 to 127 why this 128-1 in the positive side. why both side is not equal. why this one is subtracted from the right side.

byte 1 byte Stores whole numbers from -128 to 127

Write down all the integers from `-128` to `128` on a piece of paper and count how many there are. — High Performance Mark, Apr 01 '20 at 15:16
OP might care to review similar Qs and As here on SO, for example https://stackoverflow.com/questions/11433789/why-is-the-range-of-signed-byte-is-from-128-to-127-2s-complement-and-not-fro — High Performance Mark, Apr 01 '20 at 15:49

score 5 · Accepted Answer · answered Apr 01 '20 at 15:16

5

[-128, 128] contains 257 values but 8 bits can only distinguish 2⁸=256 values.

-128 to -1 is 128 values +
0 is 1 value +
1 to 128 is 128 values

answered Apr 01 '20 at 15:16

Mike Samuel

score 2 · Answer 2 · answered Apr 01 '20 at 15:17

2

That's because you count 0 as well!

1 byte is 8 bits, which is 2^8 i.e 256 numbers.

So we have 128 negative numbers (-1 to -128), a 0, and we left with only 127 positive numbers.

answered Apr 01 '20 at 15:17

Omri Attiya

2 Answers2