boolean isEmpty()

// Java code to illustrate isEmpty()
  
import java.io.*;
import java.util.*;
  
public class SortedSetDemo {
    public static void main(String args[])
    {
        // Creating an empty Set
        SortedSet<String> set
            = new TreeSet<String>();
  
        // Use add() method to
        // add elements into the Set
        set.add("Welcome");
        set.add("To");
        set.add("Geeks");
        set.add("4");
        set.add("Geeks");
  
        // Displaying the Set
        System.out.println("Set: " + set);
  
        // Check for the empty set
        System.out.println("Is the set empty? "
                           + set.isEmpty());
  
        // Clearing the set using clear() method
        set.clear();
  
        // Again Checking for the empty set
        System.out.println("Is the set empty? "
                           + set.isEmpty());
    }
}

Set: [4, Geeks, To, Welcome]
Is the set empty? false
Is the set empty? true