Extending enum in Java

Question

public enum myEnum {    
VAL1(10), VAL2(20), VAL3("hai") {
        public Object getValue() {
            return this.strVal;
        }
        public String showMsg() {
            return "This is your msg!";
        }
    };
    String strVal;
    Integer intVal;
    public Object getValue() {
        return this.intVal;
    }
    private myEnum(int i) {
        this.intVal = new Integer(i);
    }
    private myEnum(String str) {
        this.strVal = str;
    }
}

In the above enum what exactly happens when I add a constant specific class body for VAL3?

The type of VAL3 is definetly a subtype of myEnum as it has overloaded and additional methods. (the class type comes as 'myEnum$1' )

But how can the compiler creates a subtype enum extending myEnum as all the enums are already extending java.lang.enum ?

Answer 1

Your class myEnum inherits from java.lang.Enum. VAL3 is an anonymous inner class that inherits from myEnum called myEnum$1. Think of the enum keyword as syntatic sugar. It sets up classes with normal inheritance trees for you, but will not allow you to extend java.lang.Enum or myEnum directly.