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I’d like to know some cases in Java (or more generally:
in programming) when it is preferred in boolean expressions to use the unconditional AND (&) instead of the conditional version (&&).
I know how they work, but I cannot think about a case when use the single & is worth it.
I have found cases in real life where both sides of the expression were really cheap, so it shaved off a nanosecond or two to avoid the branch and to use the unconditional
&instead of&&. (These were extremely high-performance math utilities, though; I would almost never use this in other code, and I wouldn’t have done it anyway without exhaustive benchmarking to prove it was better.)(To give specific examples,
x > 0is going to be super cheap and side-effect-free. Why bother risking a branch misprediction to avoid a test that’s going to be so cheap anyway? Sure, since it’s abooleanthe end result is going to be used in a branch anyway, butif (x >= 0 && x <= 10)involves two branches, andif (x >= 0 & x <= 10)involves only one.)