在Java中使用OR进行OR运算的问题？

Question

Let's say I have the following code in java

byte t = (byte) 0b10001000;
byte z = 0b00000000;
z = (byte) (t|z);

You'd think the output would be 10001000, however it ends up being -1111000 in String representation, the - sign being the first 1 of course, making it 11111000. If I do the same code but with the last bit in z as a 1, eg 00000001, and I perform the same operation, I get -1110111, or 11110111. I figure this is due to some conversion issue with the negatively signed byte t. Is there any way to avoid this? Is there any way to have 10000000 work the same in an OR operation as 01000000?

Answer 1

Java doesn't have unsigned types, so when you use binary notaion and set the sign bit things will not go as you expect ;-)

To emulate an unsigned type you need to work in the next size up.