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
