Skip to content
Related Articles

Related Articles

TreeMap clear() Method in Java
  • Last Updated : 28 Jun, 2018

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);
    }
}


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() 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);
    }
}


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.

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up
Recommended Articles
Page :