Java Advance Concepts

HashMap vs LinkedHashMap in Java: Key Differences, Performance & Use Cases

March 18, 2026 Umang Parekh

Java developers often use HashMap for key-value storage, but LinkedHashMap offers specific advantages when order matters. Both implement the Map interface and provide O(1) time complexity for get and put operations. The key difference lies in iteration order: HashMap does not guarantee order, while LinkedHashMap maintains a linked list for either insertion or access order. LinkedHashMap is also beneficial for creating LRU caches, allowing automatic eviction of the least recently used entry. Overall, use HashMap for speed and minimal memory, and choose LinkedHashMap when order is crucial or for caching needs, as they share the same API.

Java 25: The Future of Concurrency with Virtual Threads

December 14, 2025 Umang Parekh

For years, Java developers have been told the same story: “Concurrency is hard — but powerful.” We accepted it. We learned thread pools, executors, synchronization,

Java Incubator vs Preview Features: What Developers Need to Know

November 28, 2025 Umang Parekh

The Java platform keeps evolving at a remarkable pace. With new releases arriving every six months, the language and runtime are constantly expanding with fresh

Java 25: Compact Source Files Explained

November 6, 2025 Umang Parekh

Java 25 introduces one of the most developer-friendly changes in years — Compact Source Files and Instance Main Methods (JEP 512).It’s a feature that trims

Minimum Deletion Cost to Avoid Repeating Letters

October 21, 2020 Umang Parekh

This is a Leet Code problem (1578 – Minimum Deletion Cost to Avoid Repeating Letters) solved in Java, the problem description is:

Given a string s and an array of integers cost where cost[i] is the cost of deleting the ith character in s.

Difference between Synchronized & Volatile in Java

August 20, 2019 youvcode

volatile keyword in Java is field modifier while synchronized modifies code blocks and methods. synchronized acquires and releases locks on entire code block or method

ArrayList vs. LinkedList

January 19, 2019 youvcode

Arraylist is an index based Data Structure. While using Arraylist for searching or getting an element from an array with index is pretty fast. ArrayList