Create EnumSet in Java - How to Add elements to EnumSet

Published April 04, 2022

The Java.util.EnumSet package is required to create an EnumSet, so you will have to import it first in your Java program. Unlike other set implementations, EnumSet does not have a public constructor, so you must use the predefined methods. These predefined methods include:

  • allOf (Size)- Using the allof() method, you can create an enum set containing all values of the specified enum type Size.

  • noneOf(Size)- An empty EnumSet is created with the noneOf() method.

  • range(e1,e2) Method- Range() creates an enum set which includes both values for an enum between e1 and e2 within a given range.

  • of() Method- Using the () method, an enum set containing the specified element is created.

The Methods of EnumSet

  • add(): this method inserts  the specified values into the EnumSet

  • addAll():  this method  inserts  the specified  collections  to the set

  • iterator():  this method is used to access  the Enum set elements

  • hasNext():  this method returns true if there  is a next element in the EnumSet

  • next(): this method returns  the  next elements in the EnumSet

  • remove(): this method removes  the specified  element from the EnumSet

  • removeAll(): this method removes all elements from the EnumSet

 

Example of EnumSet

import java.util.EnumSet;

import java.util.Iterator;

 

public class EnumExample {

    enum ES {

            a, b, c, d;

    }

    public static void main(String[] args) {

      // Creating EnumSet

        EnumSet<ES> sizes = EnumSet.allOf(ES.class);

        Iterator<ES> iterate = sizes.iterator();

        System.out.print("EnumSet Values: ");

        while(iterate.hasNext()) {

            System.out.print(iterate.next());

            System.out.print(", ");

    }

            }

}

 

 

Output:

EnumSet Values: a, b, c, d