Java Bitwise Or Between Byte and Int

Question

I am trying to perform a bitwise or on a byte value I have in Java.

For example, I am running:

byte b = (byte)0b11111111;
int result = 0 | b;

My expected result for this would be 0b00000000 00000000 00000000 11111111, or 255. However, I am receiving -1, or 0b11111111 11111111 11111111 11111111.

I'm assuming that Java converts my byte into an int via sign extension before performing the operation, and I was just curious if there was a way to get my desired result without using a bit mask (0b11111111).

"without using a bit mask" The answer is to use a bitmask. There isn't really a way around that in Java. — Alexis King, Jan 28 '15 at 22:16

score 7 · Accepted Answer · answered Jan 28 '15 at 22:16

7

Using a bit mask is the standard solution to disable sign extension when converting a byte to an int. You'll just have to accept this slice of Java ugliness.

int result = 0 | (b & 0xFF);

answered Jan 28 '15 at 22:16

John Kugelman

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Java Bitwise Or Between Byte and Int

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