Java Collections emptySet() Method with Examples

The emptySet() method is used to get the set that has no elements. This method is used in set collection. A set is a data structure that can store unique elements.

Syntax:

public static final <T> Set<T> emptySet()   

Parameters: This method will take no parameters.

Return Type: It will return an empty set that is immutable.

Example 1:

Java program to create an empty set

Java

import java.util.*;

public class GFG {
    // main method
    public static void main(String[] args)
    {
        // create an empty set
        Set<String> data = Collections.<String>emptySet();

        // display
        System.out.println(data);
    }
}

Output

[]

Example 2:

In this program, we are going to create an empty set and add elements to the set. This method will return an error.

Java

import java.util.*;

public class GFG {
    // main method
    public static void main(String[] args)
    {
        // create an empty set
        Set<String> data = Collections.<String>emptySet();

        // add 3 elements
        data.add("ojaswi");
        data.add("ramya");
        data.add("deepu");

        // display
        System.out.println(data);
    }
}

Output:

Exception in thread "main" java.lang.UnsupportedOperationException
    at java.util.AbstractCollection.add(AbstractCollection.java:262)
    at GFG.main(GFG.java:8)