在 Java 中有一种方法可以定义 char 类型的枚举
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In Java is there a way to define enum of type char
提问by C graphics
I was wondering if we can have enaum values of type char? I would like to do something like this:
我想知道我们是否可以拥有 char 类型的 enaum 值？我想做这样的事情：
public enum Enum {char X, char Y};
...
Enum a=Enum.X
if (a=='X')
{// do something}
without calling any extra function to convert enum to char( as I want it to be char already). Is there a way to do so?
无需调用任何额外的函数将枚举转换为字符（因为我希望它已经是字符）。有没有办法这样做？
- In fact this way I am trying to define a restricted variable of type char which only accepts one of two char values 'X' or 'Y'. So that if we give anything else such as 'z', the compiler complains.
- 事实上，我试图通过这种方式定义一个 char 类型的受限变量，它只接受两个 char 值“X”或“Y”之一。因此，如果我们给出其他任何内容，例如“z”，编译器就会抱怨。
回答by yshavit
No.
不。
But the conversion method isn't very hard, at all.
但是转换方法一点也不难。
public enum SomeChar {
X('X'), Y('Y');
public char asChar() {
return asChar;
}
private final char asChar;
SomeChar(char asChar) {
this.asChar = asChar;
}
}
And then:
接着：
if (a.asChar() == 'X') { ... }
If you don't like having the asChar field/constructor, you can even implement the getter as return name().charAt(0).
如果您不喜欢 asChar 字段/构造函数，您甚至可以将 getter 实现为return name().charAt(0)。
If you're using lombok, this becomes even easier:
如果您使用lombok，这将变得更加容易：
@RequiredArgsConstructor
@Getter
public enum SomeChar {
X('X'), Y('Y');
private final char asChar;
}
if (a.getAsChar() == 'X') { ...
Btw, an enum named Enumwould be confusing, since most people will see Enumin the source and assume it's java.lang.Enum. In general, shadowing a commonly used/imported class name is dangerous, and classes don't get more commonly imported than java.lang.*(which is always imported).
顺便说一句，命名的枚举Enum会令人困惑，因为大多数人会Enum在源代码中看到并假设它是java.lang.Enum. 一般来说，隐藏常用/导入的类名是危险的，并且类不会比java.lang.*（总是导入的）更常用。
