Java Articles | Backend Study Lab

Java Jul 1, 2026 5 min read

HashMap Collision Handling Explained

Learn how HashMap collision handling works in Java, including buckets, hashCode, equals, tree bins, load factor, bad keys, and performance.

Java Jul 1, 2026 5 min read

Learn Java equals and hashCode contracts, why they matter for HashMap and HashSet, common mistakes, records, mutability, and testing.

Algorithms Jul 1, 2026 4 min read

Learn prefix sums with Java examples, range-sum queries, subarray patterns, difference arrays, complexity, and when preprocessing is worth it.

Algorithms Jul 1, 2026 5 min read

Learn the sliding window algorithm pattern with Java examples, fixed windows, variable windows, two pointers, complexity, and common mistakes.

Algorithms Jul 1, 2026 5 min read

Learn the two pointers algorithm pattern with Java examples for sorted arrays, pairs, partitions, linked lists, complexity, and common mistakes.

Algorithms Jun 28, 2026 4 min read

Learn how binary search works, when it applies, common off-by-one mistakes, and how to implement iterative binary search in Java.

Java May 10, 2026 6 min read

A practical reference for Java collection time complexity, including ArrayList, LinkedList, HashMap, TreeMap, HashSet, and PriorityQueue.

Java Mar 15, 2026 4 min read

A practical explanation of ConcurrentHashMap in Java, including thread safety, atomic methods, iteration behavior, and common mistakes.

Java Mar 8, 2026 4 min read

Learn what HashMap load factor means in Java, how it affects resizing, memory usage, collision risk, and lookup performance.

Java Mar 1, 2026 4 min read

Compare ArrayList and LinkedList in Java by access patterns, insertion cost, memory overhead, and practical backend usage.