🗂️ Understanding HashMap in Java: A Helpful Guide for Developers and Interview Preparation

Hello, devs! 👩‍💻👨‍💻 Today, let’s dive into one of the most commonly used and powerful data structures in Java: the HashMap. Whether you are a beginner or prepping for interviews understanding HashMaps is essential. Let’s break it down step by step! 🚀

🛠️ What is a HashMap?

A HashMap in Java is part of the java.util package. It’s a key-value pair data structure, meaning each value is associated with a unique key. Here are its core features:

Key Characteristics:

• Keys are unique; values can be duplicate.
• Allows one null key and multiple null values.
• Order is not guaranteed (if you want order, use LinkedHashMap).

Java (java.util)

public class HashMap<K,V> extends AbstractMap<K,V> implements Map<K,V>, Cloneable, Serializable

⚙️ How Does HashMap Work?

HashMap relies on a hashing mechanism to store and retrieve values efficiently.