How to Retrieve a Specific Value From a HashMap Using Key?

Last Updated : 09 Feb, 2024

A HashMap is a data structure that implements a map interface in Java. It stores key-value pairs. On the key object's hashcode, it uses a hashing function for computing an index-based element. And it is used to store and retrieve values. This allows very fast lookup, addition, and removal of key-value pairs, with average O(1) time complexity.

In this article, we will learn how to retrieve a specific value from a HashMap using its key in Java.

Syntax:

HasMap.get(object key_element)

Program to Retrieve a Specific Value From a HashMap Using Key in Java

Below is the implementation of retrieving a specific value from a HashMap using its key:

Java

// Java Program to to retrieve a specific value from a HashMap using its key import java.util.HashMap; public class Main  {   public static void main(String[] args)    {          // Create a HashMap     HashMap<String, Integer> courses = new HashMap<>();          // Add key-value pairs     courses.put("Java", 30000);      courses.put("C++", 25000);     courses.put("Python", 35000);          // Retrieve value using key     String key = "Java";     Integer value = courses.get(key);           System.out.println(value);    } }