switch表达式不能是float，double或boolean [英] switch expression can't be float, double or boolean

问题描述

为什么开关表达式不允许 long ， float ， double 或 boolean 值？为什么只允许 int （以及自动提升为 int 的那些）？

Why doesn't the switch expression allow long, float, double or boolean values in Java? why is only int (and those that are automatoically promoted to int) allowed?

推荐答案

即使可行，浮动和双重也难以可靠使用 - 不要忘记在float / double上执行完全相等的匹配通常是一个坏主意无论如何，由于表示的性质。

Float and double would be awkward to use reliably even if they were possible - don't forget that performing exact equality matches on float/double is usually a bad idea anyway, due to the nature of the representation.

对于布尔值，为什么不使用如果开始？

For Boolean values, why not just use if to start with?

我不记得永远想要打开这些类型中的任何一种，说实话。您是否考虑过特定​​用例？

I can't remember ever wanting to switch on any of these types, to be honest. Do you have a particular use case in mind?

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