The java.util.TreeMap.clear() method in Java is used to clear and remove all of the elements or mappings from a specified TreeMap.
Syntax:
Tree_Map.clear()
Parameters: The method does not accept any parameters.
Return Value: The method does not return any value.
Below programs are used to illustrate the working of java.util.TreeMap.clear() Method:
Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the clear() method import java.util.*; public class Tree_Map_Demo { public static void main(String[] args) { // Creating an empty TreeMap TreeMap<Integer, String> tree_map = new TreeMap<Integer, String>(); // Mapping string values to int keys tree_map.put( 10 , "Geeks" ); tree_map.put( 15 , "4" ); tree_map.put( 20 , "Geeks" ); tree_map.put( 25 , "Welcomes" ); tree_map.put( 30 , "You" ); // Displaying the TreeMap System.out.println( "Initial Mappings are: " + tree_map); // Clearing the tree map using clear() tree_map.clear(); // Displaying the final TreeMap System.out.println( "Finally the map looks like: " + tree_map); } } |
Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You} Finally the map looks like this: {}
Program 2: Mapping Integer Values to String Keys.
// Java code to illustrate the clear() method import java.util.*; public class Tree_Map_Demo { public static void main(String[] args) { // Creating an empty TreeMap TreeMap<String, Integer> tree_map = new TreeMap<String, Integer>(); // Mapping int values to string keys tree_map.put( "Geeks" , 10 ); tree_map.put( "4" , 15 ); tree_map.put( "Geeks" , 20 ); tree_map.put( "Welcomes" , 25 ); tree_map.put( "You" , 30 ); // Displaying the TreeMap System.out.println( "Initial Mappings are: " + tree_map); // Clearing the tree map using clear() tree_map.clear(); // Displaying the final TreeMap System.out.println( "Finally the map looks like: " + tree_map); } } |
Initial Mappings are: {4=15, Geeks=20, Welcomes=25, You=30} Finally the map looks like: {}
Note: The same operation can be performed with any type of Mapping with variation and combination of different data types.