显式比较布尔常数是不好的if（b == false）in Java？ [英] Is it bad to explicitly compare against boolean constants e.g. if (b == false) in Java?

问题描述

写不好：

if (b == false) //...

while (b != true) //...

最好改为写：

Is it always better to instead write:

if (!b) //...

while (!b) //...

大概没有性能差异

为了限制主观性，我还将感谢权威编码风格指南中的任何引用，这些引用总是优选的或在何时使用。

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.

注意：变量名称 b 只是作为一个例子，ala foo 和 bar 。

Note: the variable name b is just used as an example, ala foo and bar.

推荐答案

这不一定是坏的，它只是多余。此外，实际变量名称权重很多。我更喜欢例如 if（userIsAllowedToLogin）以上 if（b）或更糟糕 if （flag）。

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).

至于性能问题，编译器以任何方式优化它。

As to the performance concern, the compiler optimizes it away at any way.

更新：对于权威来源，我无法在 Sun Coding约定，但至少 Checkstyle 有 SimplifyBooleanExpression 模块，会发出警告。

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.

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