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javaoperatorsbitwise-operatorsnotation

Notation for logic in Java

Absolutely basic Java question which I'm having a hard time finding on Google. What does the following mean:

(7 & 8) == 0?

Is that equivalent to writing:

7 == 0 || 8 == 0?

I wrote a quick main which tests this, and it seems to be the case. I just wanted to make sure I'm not missing anything.

Solution

  • Nope. & is bitwise and. It sets a bit if the corresponding bits are set in both inputs. Since in binary, 7 is 111 and 8 is 1000, they have no bits in common, so the result is 0.

    There isn't really any shorthand syntax for the thing you suggest, not on a single line. There are a few workarounds -- test for membership in a Set or BitSet, use a switch statement -- but nothing that's both as efficient and as short as just 7 == 0 || 8 == 0.