Is it bad to explicitly compare against boolean constants e.g. if (b == false) in Java?
Is it bad to write:
if (b == false) //...
while (b != true) //...
Is it always better to instead write:
if (!b) //...
while (!b) //...
Presumably there is no difference in performance (or is there?), but how do you weigh the explicitness, the conciseness, the clarity, the readability, etc between the two?
Update
To limit the subjectivity, I'd also appreciate any quotes from authoritative coding style guidelines over which is always preferable or which to use when.
Note: the variable name b is just used as an example, ala foo and bar.
Answer
It's not necessarily bad, it's just superfluous. Also, the actual variable name weights a lot. I would prefer for example if (userIsAllowedToLogin) above if (b) or even worse if (flag).
As to the performance concern, the compiler optimizes it away at any way.
Update: as to the authoritative sources, I can't find something explicitly in the Sun Coding Conventions, but at least Checkstyle has a SimplifyBooleanExpression module which would warn about that.