The java.util.EnumSet.complementOf(Enum_Set) method is used to create an EnumSet containing elements of the same type as that of the specified Enum_Set, with the values present in the enum but other than those contained in the specified Enum_Set.
Syntax:
New_Enum_Set = EnumSet.complementOf(Enum_Set)
Parameters: The method accepts one parameter Enum_Set whose values are to be neglected while populating the values into the new complemented enum set.
Return Values: The method does not return any values.
Exceptions: The method throws NullPointerException if the value Enum_Set is NULL.
Below programs illustrate the working of java.util.EnumSet.complementOf() method:
Program 1:
// Java program to demonstrate complementOf() methodimport java.util.*;  // Creating an enum of GFG typeenum GFG {    Welcome,    To,    The,    World,    of,    Geeks};  public class Enum_Set_Demo {      public static void main(String[] args)    {          // Creating an empty EnumSet        // Getting elements from GFG        EnumSet<GFG> e_set = EnumSet.of(GFG.To, GFG.Welcome,                                        GFG.Geeks);          // Displaying the empty EnumSet        System.out.println("Initial set: " + e_set);          // Cloning the set        EnumSet<GFG> final_set = EnumSet.complementOf(e_set);          // Displaying the final set        System.out.println("The updated set is:" + final_set);    }} |
Output:
Initial set: [Welcome, To, Geeks] The updated set is:[The, World, of]
Program 2:
// Java program to demonstrate complementOf() methodimport java.util.*;  // Creating an enum of CARS typeenum CARS {    RANGE_ROVER,    MUSTANG,    CAMARO,    AUDI,    BMW};  public class Enum_Set_Demo {      public static void main(String[] args)    {          // Creating an empty EnumSet        // Getting all elements from CARS        EnumSet<CARS> e_set = EnumSet.allOf(CARS.class);          // Displaying the empty EnumSet        System.out.println("Initial set: " + e_set);          // Cloning the set        EnumSet<CARS> final_set = EnumSet.complementOf(e_set);          // Displaying the final set        System.out.println("The updated set is:" + final_set);    }} |
Output:
Initial set: [RANGE_ROVER, MUSTANG, CAMARO, AUDI, BMW] The updated set is:[]
