NavigableSet isEmpty() method in Java

The java.util.NavigableSet.isEmpty() method is used to check if a NavigableSet is empty or not. It returns True if the NavigableSet is empty otherwise it returns False.

Syntax:

boolean isEmpty()

Parameters: This method does not take any parameter

Return Value: The method returns True if the NavigableSet is empty else returns False.

Below program illustrate the java.util.NavigableSet.isEmpty() method:

// Java code to illustrate isEmpty()
import java.io.*;
import java.util.*;

public class NavigableSetDemo {
    public static void main(String args[])
    {
        // Creating an empty NavigableSet
        NavigableSet<String> st = new TreeSet<String>();

        // Use add() method to add elements into
        // the NavigableSet
        st.add("Welcome");
        st.add("To");
        st.add("Geeks");
        st.add("4");
        st.add("Geeks");

        // Displaying the NavigableSet
        System.out.println("NavigableSet: " + st);

        // Check for the empty NavigableSet
        System.out.println("Is the NavigableSet empty? "
                           + st.isEmpty());

        // Clearing the NavigableSet using clear() method
        st.clear();

        // Again Checking for the empty NavigableSet
        System.out.println("Is the NavigableSet empty? "
                           + st.isEmpty());
    }
}

Output:

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