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