NavigableMap clear() Method in Java

Last Updated : 31 Oct, 2018

The clear() method of NavigableMap interface in Java is used to clear and remove all of the elements or mappings from a specified Map.

Syntax:

NavigableMap.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 clear() method:
Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the clear() method 
import java.util.*; 
  
public class NavigableMap_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty NavigableMap 
        NavigableMap<Integer, String> nav_map = new TreeMap<Integer, String>(); 
  
        // Mapping string values to int keys 
        nav_map.put(10, "Geeks"); 
        nav_map.put(15, "4"); 
        nav_map.put(20, "Geeks"); 
        nav_map.put(25, "Welcomes"); 
        nav_map.put(30, "You"); 
  
        // Displaying the NavigableMap 
        System.out.println("Initial Mappings are: " + nav_map); 
  
        // Clearing the tree map using clear() 
        nav_map.clear(); 
  
        // Displaying the final NavigableMap 
        System.out.println("Finally the map looks like: " + nav_map); 
    } 
} 

Output:

Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Finally the map looks like: {}

Program 2: Mapping Integer Values to String Keys.

// Java code to illustrate the clear() method 
import java.util.*; 
  
public class NavigableMap_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty NavigableMap 
        TreeMap<String, Integer> nav_map = new TreeMap<String, Integer>(); 
  
        // Mapping int values to string keys 
        nav_map.put("Geeks", 10); 
        nav_map.put("4", 15); 
        nav_map.put("Geeks", 20); 
        nav_map.put("Welcomes", 25); 
        nav_map.put("You", 30); 
  
        // Displaying the NavigableMap 
        System.out.println("Initial Mappings are: " + nav_map); 
  
        // Clearing the tree map using clear() 
        nav_map.clear(); 
  
        // Displaying the final NavigableMap 
        System.out.println("Finally the map looks like: " + nav_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.

NavigableMap floorEntry() method in Java

chinmoy lenka

Improve

Article Tags :

Practice Tags :

Java

NavigableMap clear() Method in Java

Similar Reads

Thank You!

What kind of Experience do you want to share?