SortedMap size() method in Java with Examples

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

Syntax:

int size()

Parameters: The method does not take any parameters.

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

Note: The size() method in SortedMap is inherited from the Map interface in Java.

Below programs illustrate the working of size() method:

Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the size() method

import java.util.*;

public class Gfg {
    public static void main(String[] args)
    {

        // Creating an empty SortedMap
        SortedMap<Integer, String> map
            = new TreeMap<Integer, String>();

        // Mapping string values to int keys
        map.put(10, "Geeks");
        map.put(15, "4");
        map.put(20, "Geeks");
        map.put(25, "Welcomes");
        map.put(30, "You");

        // Displaying the SortedMap
        System.out.println(
            "Initial Mappings are: "
            + map);

        // Displaying the size of the map
        System.out.println(
            "The size of the map is "
            + map.size());
    }
}

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.

// Java code to illustrate the size() method

import java.util.*;

public class Gfg {
    public static void main(String[] args)
    {

        // Creating an empty SortedMap
        SortedMap<String, Integer> map
            = new TreeMap<String, Integer>();

        // Mapping int values to string keys
        map.put("Geeks", 10);
        map.put("4", 15);
        map.put("Geeks", 20);
        map.put("Welcomes", 25);
        map.put("You", 30);

        // Displaying the SortedMap
        System.out.println(
            "Initial Mappings are: "
            + map);

        // Displaying the size of the map
        System.out.println(
            "The size of the map is "
            + map.size());
    }
}

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.

Reference: https://docs.oracle.com/javase/9/docs/api/java/util/Map.html#size–