last bit in data type

[nada saif]

Hi ,

I am confused about how to define the limits of data in examples we say byte starts from -128 and stops at 127

How we can use -128 as i know the last bit is just for sign ???


Best,

Nada

[Henry Wong]

The representation is not as simple as 7 bits for the value and one bit for the sign (independently). There is one bit for the sign, but the eight bits needs to be evaluated together to get the overall value.

Basically, Java uses two complement to represent bytes, shorts, ints, and longs.

http://en.wikipedia.org/wiki/Two's_complement

Henry