When all the keys of a Map are values from the same enum, the ``++Map++`` can be replaced with an ``++EnumMap++``, which can be much more efficient than other sets because the underlying data structure is a simple array.


== Noncompliant Code Example

----
public class MyClass {

  public enum COLOR {
    RED, GREEN, BLUE, ORANGE;
  }

  public void mapMood() {
    Map<COLOR, String> moodMap = new HashMap<COLOR, String> ();
  }
}
----


== Compliant Solution

----
public class MyClass {

  public enum COLOR {
    RED, GREEN, BLUE, ORANGE;
  }

  public void mapMood() {
    EnumMap<COLOR, String> moodMap = new EnumMap<> (COLOR.class);
  }
}
----