在Java中的布尔前pressions [英] Boolean expressions in Java

问题描述

我有一个布尔变量在Java中return语句的含义（评价）的问题。

I have a question about the meaning (evaluation) of Boolean variables in return statements in Java.

我知道：

if (var) { ... }

是相同的：

if (var==true) { ... }

在第二种情况下，我们明确地说，VAR ==真实的，但我们并不需要这样做，因为Java评估var当成真正的反正。我希望我已经明白这个权利。

In the second case we explicitly say var==true, but we don't need to do this, because Java evaluates var as true anyway. I hope I have understood this right.

我的问题是：这是相同的，当返回布尔变量？当我们有一个return语句？

My question is: is it the same when Boolean variables are returned? When we have a return statement?

例如，一个任务规定：该方法looksBetter（）将返回true，只有当B＆LT;一个。我的解决办法是：

For example, a task specifies: the method looksBetter() will return true only if b < a. My solution was:

public boolean looksBetter() {
     if (b < a) {
         return true;
     } else {
         return false;
     }
}

简单的答案是：

public boolean lookBetter() {
      return b < a;
}

所以，看来在这里，我们有这又隐含的假设的情况下，B＆LT;一个== true，则该方法的返回是真实的。
我很抱歉......看起来很琐碎，但我有点不舒服这一点，我不知道为什么。谢谢你。

So, it seems that here we have again this implicit assumption that in case b < a == true, the return of the method is true. I am sorry ... it seems very trivial, but I am somehow not comfortable with this, and I don't know why. Thank you.

推荐答案

这不是一个隐含的假设，这就是编译器的做。在 B＆LT;一个只是一个前pression，一样的，如果它被用于一个如果语句。这位前pression计算结果为布尔，然后返回。

It's not an "implicit assumption," it's what the compiler's doing. The b < a is just an expression, the same as if it were used for an if statement. The expression evaluates to a boolean, which is then returned.

另外值得一提，你似乎交汇处布尔和布尔好像它们是相同的，但他们其实不重。 布尔是的原始形式，而布尔是的一个封装了布尔对象 。

Also noteworthy, you seem to interchange boolean and Boolean as though they're the same, but they're actually not. boolean is the primitive form while Boolean is an Object that wraps a boolean.

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