Java 11 and 12 – New Features

Workarounds to access enum constants

One of the ways to access members such as variables and methods that are specific to an enum constant is—to define them for all members, but only allow the usage for specific members (I know, this is not recommended). I've removed code that is not relevant to show how this works, as follows:

enum Size {    SMALL(36, 19),    MEDIUM(32, 20),    LARGE(34, 22);    int length;                            // instance variable                                            //accessible    int width;                             // to all enum constants    Size(int length, int width) {          // enum constructor; accepts                                             //length         this.length = length;             // and width         this.width = width;    }    int getSize() {       if (this == MEDIUM)         return length + width;       else                                           // throws runtime                                                       // exception throw new UnsupportedOperationException(); // if used with ...