java - javac如何计算public static final int NaN = 0/0？

Question

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已关闭 10 年前。

我想知道javac如何计算这个常量表达式？

class Test {
   public static final int NaN = 0 / 0;
...

Answer 1

它在 Java Language Specification, §15.17.2 中定义:

There is one special case that does not satisfy this rule: if the dividend is the negative integer of largest possible magnitude for its type, and the divisor is -1, then integer overflow occurs and the result is equal to the dividend. Despite the overflow, no exception is thrown in this case. On the other hand, if the value of the divisor in an integer division is 0, then an ArithmeticException is thrown.

这意味着什么:如果被除数为 0，那么除数是多少并不重要；它会直接抛出ArithmeticException。

现在，如果您使用 double ，那么JLS §15.17.2将返回NaN .