Map get() method in Java with Examples

The get() method of Map interface in Java 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. So, let us check how to get value from the map in Java.

Syntax of get() method in Java

thisMap.get(Object key_element)

Parameter and Return Value of get() method

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 this Map collection.

Return Type  of get() method

The Return Type of the get() method depends on the data type or what datatypes we have passed in the parameter. Below we have mentioned two cases explaining how to use get() method and to get which return type.

Case 1: 

In this case, the return type of get() method will be Integer because the data type initialized in map key value is Integer.

Map<String,Integer> map=new HashMap<>();

Below is the Implementation of the above Case:

Java

// Java Program to demonstrate
// Mapping Integer Values to String Keys.

import java.util.*;

public class Map_Demo {
    public static void main(String[] args)
    {
        // Creating an empty Map
        Map<String, Integer> map = new HashMap<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 Map
        System.out.println("Initial Mappings are: " + map);

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

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

Output:

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

Case 2:

Here it will return String.

Map<Integer,String> map=new HashMap<>();

The below programs illustrate the working of java.util.Map.get() method.

Java

// Java Program to demonstrate the
// Mapping String Values to Integer Keys
import java.util.*;

public class Map_Demo {
    public static void main(String[] args)
    {
        // Creating an empty Map
        Map<Integer, String> map = new HashMap<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 Map
        System.out.println("Initial Mappings are: " + map);

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

        // Getting the value of 10
        System.out.println("The Value is: " + 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

Note: The same operation can be performed with any type of Mappings with variation and combination of different data types. The return type will depend on the data type passed in the HashMap.

Reference: Official documentation