TreeSet isEmpty() Method in Java
The Java.util.TreeSet.isEmpty() method is used to check and verify if a TreeSet is empty or not. It returns True if the TreeSet is empty else it returns False.
Syntax:
Tree_Set.isEmpty()
Parameters: The method does not take any parameter
Return Value: The function returns True if the set is empty else it returns False.
Below program illustrate the use of Java.util.TreeSet.isEmpty() method:
// Java code to illustrate isEmpty() method import java.util.*; import java.util.TreeSet; public class TreeSetDemo { public static void main(String args[]) { // Creating an empty HashSet TreeSet<String> tree = new TreeSet<String>(); // Use add() method to add elements into the Set tree.add( "Welcome" ); tree.add( "To" ); tree.add( "Geeks" ); tree.add( "4" ); tree.add( "Geeks" ); tree.add( "TreeSet" ); // Displaying the TreeSet System.out.println( "TreeSet: " + tree); // Check for the empty set System.out.println( "Is the set empty? " + tree.isEmpty()); // Clearing the set using clear() method tree.clear(); // Again Checking for the empty set System.out.println( "Is the set empty? " + tree.isEmpty()); } } |
Output:
TreeSet: [4, Geeks, To, TreeSet, Welcome] Is the set empty? false Is the set empty? true