Is it better to use class.isEnum() or instanceof Enum?
I have an object. I want to check to see if it is of type enum. There are two ways to do this.
object.getClass().isEnum()
or
object instanceof Enum
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Is one better?
In my opinion object instanceof Enum
is better for several reasons:
- It is very obvious what is asked here: "is this an enum"?
- It doesn't risk a
NullPointerException
(ifobject
isnull
, it will just evaluate tofalse
) - It's shorter.
The only reason I'd see for using isEnum()
would be if I only have access to the Class
object and not to a concrete instance.
You need to use the latter (object instanceof Enum
) because the former may not work with enum constants with constant-specific class bodies.
For example, for this enum type:
enum MyEnum {
FOO { }
}
The expression MyEnum.FOO.getClass().isEnum()
returns false
.
If you want to check if an object is a enum constant without instanceof Enum
, you have to use this (much more complicated) expression:
static boolean isEnum(Object obj) {
Class<?> cls = obj.getClass();
Class<?> superCls = cls.getSuperclass();
// Be careful, Object.class.getSuperclass() returns null
return cls.isEnum() || (superCls != null && superCls.isEnum());
}
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