Question

I have some enums, all different, and I want to create a function that can find or not if a string is one of enum variable name (not sure it’s really understandable).

enum MYENUM {
  ONE,
  TWO;
}

enum MYENUM1 {
  RED,
  GREEN;
}

I want to do this (this is just for the example, my enum are more complicated):

if(isInEnum(MYENUM, "one")) ...
if(isInEnum(MYENUM1, "one")) ...

isinEnum function (the code is bad, it’s just for understanding):

boolean isinEnum(enum enumeration, String search) {
  for(enum en : enumeration.values()){
    if(en.name().equalsIgnoreCase(search)) return true;
  }
  return false;
}

Is this kind of thing possible?

I think not, according to what I can read on the web, but maybe someone has a solution to do this, instead of making one loop for each enum.

Answer 1

Here is a way using reflection…

public class EnumFinder {

    public static <T extends Enum<T>>  boolean isInEnum(Class<T> clazz, String name) {
        for (T e : clazz.getEnumConstants()) {
            if (e.name().equalsIgnoreCase(name)) {
                return true;
            }
        }

        return false;
    }

    public static void main(String[] argv) {
        System.out.println(isInEnum(MYENUM.class, "one"));   // true
        System.out.println(isInEnum(MYENUM1.class, "one"));  // false
    }
}

Your attempt in your answer was actually very close. The only difference is that Java needs an instance of the defining class in order to answers questions about an unknown type dynamically at runtime.