How to get number of possible items of an Enum?

Question

Is there a builtin way to get the number of items of an Enum with something like Myenum.length,

Or do I have to implement myself a function int size() hardcording the number of element?

Answer 1

Yes you can use the Enum.values() method to get an array of Enum values then use the length property.

public class Main {
    enum WORKDAYS { Monday, Tuesday, Wednesday, Thursday, Friday; }

    public static void main(String[] args) {
        System.out.println(WORKDAYS.values().length);
        // prints 5
    }
}

http://ideone.com/zMB6pG

Answer 2

You can get the length by using Myenum.values().length

The Enum.values() returns an array of all the enum constants. You can use the length variable of this array to get the number of enum constants.

Assuming you have the following enum:

public enum Color
{
    BLACK,WHITE,BLUE,GREEN,RED
}

The following statement will assign 5 to size:

int size = Color.values().length;