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  1. HashMap (Java Platform SE 8 ) - Oracle

    Hash table based implementation of the Map interface. This implementation provides all of the optional map operations, and permits null values and the null key. (The HashMap class is roughly equivalent …

  2. Java HashMap - W3Schools

    It is part of the java.util package and implements the Map interface. Instead of accessing elements by an index (like with ArrayList), you use a key to retrieve its associated value.

  3. A Guide to Java HashMap - Baeldung

    Jan 16, 2025 · In this tutorial, we’ll see how to use HashMap in Java, and we’ll look at how it works internally. A class very similar to HashMap is Hashtable. Please refer to a couple of our other articles …

  4. How Java HashMaps Work – Internal Mechanics Explained

    Aug 9, 2024 · In this article, I will introduce you to HashMap s in Java. We will explore the common operations of HashMap and then delve into how it operates internally. You will gain an understanding …

  5. Complete Guide to Java HashMap (with Examples) - HowToDoInJava

    Dec 5, 2024 · The HashMap, part of the Java Collections framework, is used to store key-value pairs for quick and efficient storage and retrieval operations. In the key-value pair (also referred to as an …

  6. HashMap Class Methods in Java with Examples - GeeksforGeeks

    Jul 23, 2025 · HashMap is a data structure that uses a hash function to map identifying values, known as keys, to their associated values. It contains "key-value" pairs and allows retrieving value by key.

  7. Java HashMap (With Examples) - Programiz

    The HashMap class provides the functionality of the hash table data structure in Java. In this tutorial, we will learn about the Java HashMap class and its various operations with the help of examples.

  8. What is a HashMap in Java? - Educative

    Oct 31, 2025 · In this blog, we will explore what the Java HashMap is, including coding examples, their benefits, and potential disadvantages. A Java HashMap stores key-value pairs where each key is …

  9. Java HashMap - Codecademy

    May 17, 2025 · A HashMap is an important part of the Java collections framework and implements the Map interface. It stores items as key-value pairs, where each key is unique and is used to fetch the …

  10. HashMap (Java SE 21 & JDK 21) - Oracle

    Hash table based implementation of the Map interface. This implementation provides all of the optional map operations, and permits null values and the null key. (The HashMap class is roughly equivalent …