TreeMap get() Method in Java

Difficulty Level : Easy
Last Updated : 28 Jun, 2018

The java.util.TreeMap.get() method of TreeMap class is used to retrieve or fetch the value mapped by a particular key mentioned in the parameter. It returns NULL when the map contains no such mapping for the key.

Syntax:

Tree_Map.get(Object key_element)

Parameter: The method takes one parameter key_element of object type and refers to the key whose associated value is supposed to be fetched.

Return Value: The method returns the value associated with the key_element in the parameter.

Below programs illustrates the working of java.util.TreeMap.get() method:
Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the get() 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);
  
        // Getting the value of 25
        System.out.println("The Value is: " + tree_map.get(25));
  
        // Getting the value of 10
        System.out.println("The Value is: " + tree_map.get(10));
    }
}

Output:

Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The Value is: Welcomes
The Value is: Geeks

Program 2: Mapping Integer Values to String Keys.

// Java code to illustrate the get() 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);
  
        // Getting the value of "Geeks"
        System.out.println("The Value is: " + tree_map.get("Geeks"));
  
        // Getting the value of "You"
        System.out.println("The Value is: " + tree_map.get("You"));
    }
}

Output:

Initial Mappings are: {4=15, Geeks=20, Welcomes=25, You=30}
The Value is: 20
The Value is: 30

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

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