How to use enum with grouping and subgrouping hierarchy/nesting

Question

I have one enum \'class\' called Example as follows:

enum Example {
//enums belonging to group A:
   enumA1,
   enumA2,
   enumA3,
//en         


        

Answer 1

You can use EnumSet to group various enums without creating a separate Enum class:

public enum Example {

    ENUM_A1, ENUM_A2, ENUM_A3,
    ENUM_B1, ENUM_B2, ENUM_B3,
    ENUM_C1, ENUM_C2, ENUM_C3;

    public static EnumSet groupA = EnumSet.of(ENUM_A1, ENUM_A2, ENUM_A3);
    public static EnumSet groupB = EnumSet.of(ENUM_B1, ENUM_B2, ENUM_B3);
    public static EnumSet groupC = EnumSet.of(ENUM_C1, ENUM_C2, ENUM_C3);

}   

public static void main(String[] args){
    if(Example.groupA.contains(Example.ENUM_A1)){
       System.out.println("Group A contains ENUM A1");
    }
}