Java Map get() example

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

In this guide, you will learn about the Map get() method in Java programming and how to use it with an example.

1. Map get() Method Overview

Definition:

The get() method of the Java Map interface retrieves the value to which the specified key is mapped, or null if the map contains no mapping for the key.

Syntax:

V value = map.get(Object key);

Parameters:

- key: The key whose associated value is to be returned.

Key Points:

- If the map contains a mapping for the specified key, this method returns the associated value.

- If the map doesn't contain the specified key, it returns null.

- The method allows null as a key. If the map contains a mapping for a null key, then this method can return the value associated with that key.

- If the map implementation allows for null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it could also mean that the map explicitly maps the key to null.

2. Map get() Method Example

import java.util.HashMap;
import java.util.Map;

public class MapGetExample {
    public static void main(String[] args) {
        Map<String, Integer> fruitsCount = new HashMap<>();

        // Populate the map
        fruitsCount.put("Apple", 10);
        fruitsCount.put("Banana", null);
        fruitsCount.put(null, 5);

        // Get values using keys
        System.out.println(fruitsCount.get("Apple"));     // 10
        System.out.println(fruitsCount.get("Banana"));    // null
        System.out.println(fruitsCount.get("Cherry"));    // null
        System.out.println(fruitsCount.get(null));        // 5
    }
}

Output:

10
null
null
5

Explanation:

In this example:

1. We create a HashMap and populate it with three key-value pairs. One of these pairs has a null key, and another has a null value.

2. We then use the get() method to retrieve the values associated with various keys:

- Retrieving the value for "Apple" gives us 10.

- Retrieving the value for "Banana" gives us null. This indicates that "Banana" is mapped to null, not that "Banana" is absent from the map.

- Retrieving the value for "Cherry" also gives us null, but in this case, it's because "Cherry" is not in the map.

- Finally, retrieving the value for a null key gives us 5.

The get() method is fundamental when working with maps as it provides a way to fetch the value associated with a particular key. It's essential to understand its behavior, especially when dealing with null keys or values.

Related Map Interface methods

Java Map put() example
Java Map get() example
Java Map remove() example
Java Map containsKey() example
Java Map containsValue() example
Java Map keySet() example
Java Map values() example
Java Map entrySet() example

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF