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Binary representation of -128

Greenhorn
Posts: 17
Hi
We know the range of byte is -128 to +127.
I want to know how -128 is represented in binary system

Greenhorn
Posts: 26
-128 in a byte is represented as 1000 0000

Naveed Hassan
Greenhorn
Posts: 17
Well, then is there any idea for -0 (negative zero) in JAVA?

Ranch Hand
Posts: 52
there is no -0 in integer, for integer, -0 and +0 are the same.
There is -0.0 and +0.0 for float and double.

Ranch Hand
Posts: 91
how do u get the binary of -128?
thanks

tumbleweed
Posts: 5089
You start counting
0 = 0000 0000
+ 1 = 0000 0001
+ 127 = 0111 1111
- 128 = 1000 0000 (the left-most bit is the sign bit)
- 127 = 1000 0001 (you add 1 remember)
- 1 = 1111 1111

Johannes de Jong
tumbleweed
Posts: 5089

Negative Numbers In Binary
Negative numbers in Binary are almost always displayed in "2's Complement" form.
For a negative number, invert all the bits of it's positive counterpart and add one. For Instance, in 16-bit decimal numbers:
1 = %0000 0000 0000 0001
Inverting the bits gives: %1111 1111 1111 1110
Adding 1 gives: %1111 1111 1111 1111 = -1

See : http://www.rz.uni-hohenheim.de/rz/sys/basics/csc102/ch2.html#bin_not

Ranch Hand
Posts: 95
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