Last Updated : 11 Jul, 2025
size() method of TreeMap class is used to get the size of the map which refers to the number of the key-value pair or mappings in the Map.
--> java.util package
--> TreeMap class
--> size() Method
Syntax:
Tree_Map.size()
Return Value: The size of the map which also means the number of key-value pairs present in the map.
Example 1: Mapping String Values to Integer Keys
Java
// Java Program to Illustrate size() Method
// of TreeMap class
// Importing required classes
import java.util.*;
// Main class
public class GFG {
// Main driver method
public static void main(String[] args)
{
// Creating an empty TreeMap by
// declaring object of Integer, string pairs
TreeMap<Integer, String> tree_map
= new TreeMap<Integer, String>();
// Mapping string values to int keys
// using put() method
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 elements of TreeMap
System.out.println("Initial Mappings are: "
+ tree_map);
// Now displaying the size of this map
// using size() method
System.out.println("The size of the map is "
+ tree_map.size());
}
}
Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The size of the map is 5
Example 2: Mapping Integer Values to String Keys
Java
// Java Program to Illustrate the size() method
// of TreeMap class
// Importing required classes
import java.util.*;
// Main class
public class GFG {
// Main driver method
public static void main(String[] args)
{
// Creating an empty TreeMap by
// declaring object of string, integer pairs
TreeMap<String, Integer> tree_map
= new TreeMap<String, Integer>();
// Mapping int values to string keys
// using put() method
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);
// Printing the elements of TreeMap
System.out.println("Initial Mappings are: "
+ tree_map);
// Printing the size of the map
// using size() method
System.out.println("The size of the map is "
+ tree_map.size());
}
}
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.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4