Java Utility Library

Java EnumSet - of() Method

The java.util.EnumSet.of() method is used to create an enum set initially containing the specified elements.

Syntax

public static <E extends Enum<E>> EnumSet<E> of(E e1, 
                                                E e2, E e3)

Here, E is the type of element maintained by the container.

Parameters

`e1`	Specify an element that this set is to contain initially.
`e2`	Specify another element that this set is to contain initially.
`e3`	Specify another element that this set is to contain initially.

Return Value

Returns an enum set initially containing the specified elements.

Exception

Throws NullPointerException, if any parameters are null.

Example:

In the example below, the java.util.EnumSet.of() method is used to create an enum set initially containing the specified elements.

import java.util.*;

public class MyClass {
  
  //creating an enum
  public enum weekday{
    SUN, MON, TUE, WED, THU, FRI, SAT
  }

  public static void main(String[] args) {
    //creating an EnumSet
    EnumSet<weekday> Set;

    //Add elements using of() method
    Set = EnumSet.of(weekday.SUN, weekday.MON, weekday.TUE);
    
    //print the content of Set
    System.out.println("Set contains: "+ Set);  

    //Add another set of elements using of() method
    //which replaces the previous elements
    Set = EnumSet.of(weekday.WED, weekday.THU, weekday.FRI);

    //print the content of Set
    System.out.println("Set contains: "+ Set); 
  }
}

The output of the above code will be:

Set contains: [SUN, MON, TUE]
Set contains: [WED, THU, FRI]

❮ Java.util - EnumSet