HashMap get() Method in Java

The java.util.HashMap.get() method of HashMap 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:

Hash_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.HashMap.get() method:
Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the get() method
import java.util.*;

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

        // Creating an empty HashMap
        HashMap<Integer, String> hash_map = new HashMap<Integer, String>();

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

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

        // Getting the value of 25
        System.out.println("The Value is: " + hash_map.get(25));

        // Getting the value of 10
        System.out.println("The Value is: " + hash_map.get(10));
    }
}

Output:

Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
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 Hash_Map_Demo {
    public static void main(String[] args)
    {

        // Creating an empty HashMap
        HashMap<String, Integer> hash_map = new HashMap<String, Integer>();

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

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

        // Getting the value of "Geeks"
        System.out.println("The Value is: " + hash_map.get("Geeks"));

        // Getting the value of "You"
        System.out.println("The Value is: " + hash_map.get("You"));
    }
}

Output:

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