为什么 Java 不允许在方法中定义枚举? [英] Why doesn't Java allow enum to be defined within a method?

问题描述

可能的重复:
Java:本地枚举

为什么我们不能在java中的特定方法中定义枚举?如果我有一个场景，我将在方法中使用这些枚举值，而不是在任何其他地方.在方法中声明而不是在全局定义它不是很好吗?我的意思是公开或默认.

Why do we cannot define enum within a specific method in java? If I have a scenario where I will be using those enum values in a method only not at any other place. Wouldn't it be nice to declare in method rather defining it at globally? i mean as public or default.

推荐答案

您不能在方法级别定义 JavaDocs.(我希望看到一种允许这样做的语言)

You cannot define at the method level as stated by the JavaDocs. (I would like to see a language that allowed that)

嵌套的枚举类型是隐式静态的.允许将嵌套的枚举类型显式声明为静态.

Nested enum types are implicitly static. It is permissible to explicitly declare a nested enum type to be static.

这意味着无法定义本地(第 14.3 节)枚举，或在内部类(第 8.1.3 节)中定义枚举.

This implies that it is impossible to define a local (§14.3) enum, or to define an enum in an inner class (§8.1.3).

你可以做的事情是在类级别声明它并在方法级别声明一个变量:

What you can do it declare it at the class level and a variable at the method level:

public class Light {
    ...
    private LightSwitch position;
    private enum LightSwitch {
        On,
        Off
    }
    public void SwitchOn() {
        Switch(LightSwitch.On);
    }
    public void SwitchOff() {
        Switch(LightSwitch.Off);
    }
    private void Switch(LightSwitch pos) {
        position = pos;
    }
}

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