TreeMap clear() Method in Java
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() methodimport 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); }} |
Output:
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() methodimport 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); }} |
Output:
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.
