What is HashMap A HashMap is a data structure that provides a way to store and retrieve key-value pairs. It is part of the Java Collections Framework, but similar data structures exist in other programming languages as well, often with different names (e.g., dictionaries in Python, associative arrays in PHP, or unordered_map in C++). In a HashMap, keys and values are associated with each other. The key is used to index the value, allowing for efficient retrieval of the value when the key is known. The key-value pairs in a HashMap are not ordered, meaning that there is no guaranteed order of iteration over the elements. Watch now - https://www.youtube.com/watch?v=E0-c7H5VNp0