在Java中有一种方法来定义char类型的枚举

Question

I was wondering if we can have enaum values of type char? I would like to do something like this:

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?

• 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.

Answer 1

No.

But the conversion method isn't very hard, at all.

public enum SomeChar {
    X('X'), Y('Y');

    public char asChar() {
        return asChar;
    }

    private final char asChar;

    SomeChar(char asChar) {
        this.asChar = asChar;
    }
}

And then:

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) .

If you're using lombok , this becomes even easier:

@RequiredArgsConstructor
@Getter
public enum SomeChar {
    X('X'), Y('Y');
    private final char asChar;
}

if (a.getAsChar() == 'X') { ...

---

Btw, an enum named Enum would be confusing, since most people will see Enum in 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).