NavigableMap size() Method in Java

The size() method of NavigableMap interface is used to get the size of the map which refers to the number of the key-value pair or mappings in the Map.

Syntax:

NavigableMap.size()

Parameters: The method does not take any parameters.



Return Value: The method returns the size of the map which also means the number of key-value pairs present in the map.

Below programs illustrate the working of size() method:
Program 1: Mapping String Values to Integer Keys.

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code to illustrate the size() 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);
  
        // Displaying the size of the map
        System.out.println("The size of the map is " + nav_map.size());
    }
}

chevron_right


Output:

Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The size of the map is 5

Program 2: Mapping Integer Values to String Keys.

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code to illustrate the size() method
import java.util.*;
  
public class NavigableMap_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty TreeMap
        NavigableMap<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);
  
        // Displaying the size of the map
        System.out.println("The size of the map is " + nav_map.size());
    }
}

chevron_right


Output:

Initial Mappings are: {4=15, Geeks=20, Welcomes=25, You=30}
The size of the map is 4

Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.



My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.