Mohammed Usman shaik’s Post

🚀 Mastering TreeSet in Java: Hierarchy & Powerful Methods While diving deeper into the Java Collections Framework, I explored the structure and capabilities of TreeSet—a class that combines sorting, uniqueness, and efficient navigation. 🔷 TreeSet Hierarchy (Understanding the Backbone) The hierarchy of TreeSet is what gives it its powerful features: 👉 TreeSet ⬇️ extends AbstractSet ⬇️ implements NavigableSet ⬇️ extends SortedSet ⬇️ extends Set ⬇️ extends Collection ⬇️ extends Iterable 💡 This layered structure enables TreeSet to support sorted data, navigation operations, and collection behavior seamlessly. 🔷 Important Methods in TreeSet TreeSet provides several methods for efficient data handling and navigation: 📌 Basic Retrieval first() → Returns the first (smallest) element last() → Returns the last (largest) element 📌 Range Operations headSet() → Elements less than a given value tailSet() → Elements greater than or equal to a value subSet() → Elements within a specific range 📌 Removal Operations pollFirst() → Removes and returns first element pollLast() → Removes and returns last element 📌 Navigation Methods ceiling() → Smallest element ≥ given value floor() → Largest element ≤ given value higher() → Element strictly greater than given value lower() → Element strictly less than given value 🔷 When to Use TreeSet? TreeSet is the right choice when you need: ✔️ Sorted Order (automatic ascending order) ✔️ No Duplicate Entries ✔️ Efficient Range-Based Operations ✔️ Navigation through elements (closest matches) 📊 Time Complexity: Insertion → O(log n) Access/Search → O(log n) 💡 Key Insight: TreeSet internally uses a self-balancing tree (Red-Black Tree), which ensures consistent performance and sorted data at all times. 🎯 Understanding TreeSet not only strengthens your knowledge of collections but also helps in solving real-world problems involving sorted and dynamic datasets. #Java #TreeSet #JavaCollections #Programming #DataStructures #LearningJourney TAP Academy

Day 53 of Sharing What I’ve Learned 🚀 ArrayDeque in Java — Fast & Flexible Queue Alternative After understanding how LinkedList works as a Queue, I explored a more optimized and powerful structure in the Java Collections Framework — ArrayDeque 🔹 What is ArrayDeque? ArrayDeque is a resizable array-based implementation of a Deque (Double-Ended Queue). 👉 It allows insertion and deletion from both ends efficiently. 🔹 Why use ArrayDeque over LinkedList? ✔ Faster Performance No node traversal → better speed compared to LinkedList. ✔ No Extra Memory Overhead Doesn’t store pointers like LinkedList → more memory efficient. ✔ Better Cache Performance Elements are stored contiguously → faster access. ✔ Acts as Stack + Queue Can be used as: Stack (LIFO) Queue (FIFO) Deque (both ends) 🔹 Key Operations ✔ addFirst() / addLast() ✔ removeFirst() / removeLast() ✔ peekFirst() / peekLast() 🔹 When should we use ArrayDeque? 👉 Use ArrayDeque when: ✔ You need fast insertions/deletions at both ends ✔ You want a better alternative to Stack or LinkedList ✔ Performance matters (less overhead) 🔹 When NOT to use? ❌ When you need random access (indexing) ❌ When frequent middle operations are required 🔹 Key Insight 💡 Not all Queues are equal — 👉 Choosing the right implementation (LinkedList vs ArrayDeque) can significantly impact performance. 🔹 Day 53 Realization 🎯 Efficiency isn’t just about solving problems — 👉 It’s about solving them smartly with the right tools. #Java #ArrayDeque #DataStructures #CollectionsFramework #Programming #DeveloperJourney #100DaysOfCode #Day53 Grateful for guidance from, Sharath R TAP Academy

🚀 Day 56 & 57 – Mastering Maps in Java | Tap Academy Diving deeper into the Java Collections Framework, I explored one of the most powerful concepts — Maps, especially HashMap, LinkedHashMap, and TreeMap. 🔹 Day 56 Highlights – HashMap Understood how Map stores data in key–value pairs Learned internal working: Hashing (Hash Table + Hash Function) Explored default capacity (16) and load factor (75%) Practiced key features: ✔ No duplicate keys ✔ Allows null values ✔ Heterogeneous data support ✔ Fast operations → O(1) 💻 Implemented important methods: put(), get(), containsKey(), containsValue(), entrySet(), keySet(), values() 🔁 Learned how to iterate using: entrySet() (Map → Set conversion) Iterator (cursor-based access) 🔹 Day 57 Highlights – LinkedHashMap & TreeMap 📌 LinkedHashMap Maintains insertion order Same features as HashMap but ordered output 📌 TreeMap Stores data in sorted order (ascending by keys) Uses Tree structure (Red-Black Tree) No null keys allowed Slightly slower → O(log n) 📊 Comparison Insight HashMap → Fastest, no order ⚡ LinkedHashMap → Maintains insertion order 📌 TreeMap → Sorted order 🔄 🎯 Key takeaway: Choosing the right data structure matters based on requirement — speed, order, or sorting. 🎯 This journey is strengthening my problem-solving skills and deepening my understanding of how real-world data is handled efficiently. #Java #CollectionsFramework #HashMap #LinkedHashMap #TreeMap #DataStructures #FullStackJava #TapAcademy #LearningJourney 🚀

ArrayDeque in Java Collections Continuing my deep dive into the Java Collections Framework, today I explored ArrayDeque, a powerful class for efficient data manipulation. 🔹 What is ArrayDeque? ArrayDeque is a class that implements the Deque (Double-Ended Queue) interface. It allows insertion and deletion from both ends (front & rear). 🔹 Key Characteristics Does not support indexing → no get(index) methods Default capacity → 16 Resizing → capacity grows as current × 2 Maintains insertion order Allows duplicates Allows heterogeneous data ❌ Does not allow null values 👉 Why null is not allowed? Because methods like poll() and peek() return null when the deque is empty. If null elements were allowed, Java wouldn’t be able to differentiate between: “No element” “Actual null value” 🔹 Constructors ArrayDeque() → default ArrayDeque(int capacity) → custom size ArrayDeque(Collection c) → from another collection 🔹 Hierarchy ArrayDeque → Deque → Queue → Collection → Iterable 🔹 Important Methods addFirst(), addLast() removeFirst(), removeLast() peek(), poll() offer(), offerFirst(), offerLast() 🔹 Traversal forEach() Iterator → forward traversal DescendingIterator → reverse traversal 👉 Traditional for loop & ListIterator not applicable (no indexing) 🔹 Performance Insertion/Deletion (both ends) → O(1) Faster than Stack and LinkedList for queue operations 🔹 When to Use? When you need fast insertion/removal at both ends When indexing is not required Preferred over Stack for stack operations 🔹 Learning Outcome Clear understanding of Deque structure Difference between index-based vs non-index structures Better decision-making for choosing the right collection Grateful to Tap Academy for building strong data structure foundations 🚀 🙌 Special thanks to the amazing trainers at TAP Academy: kshitij kenganavar Sharath R MD SADIQUE Bibek Singh Vamsi yadav Harshit T Ravi Magadum Somanna M G Rohit Ravinder TAP Academy #TapAcademy #Week13Learning #CoreJava #CollectionsFramework #ArrayDeque #DataStructures #JavaFundamentals #LearningByDoing #FullStackJourney #VamsiLearns

#Day45 – Map in Java: Key-Value Pairs & Problem Solving -#Programming ⚠️ Today, I explored one of the most powerful data structures in Java — Map, which helps in storing data in key-value pairs and solving real-world problems efficiently. 💡 Key Learnings: ✔ Map → collection of key-value pairs ✔ Key → unique (no duplicates allowed) and Value → can have duplicates ✔ One key maps to exactly one value ✔ Methods: put(), get(), remove(), containsKey(), containsValue() ✔ keySet() → get all keys , values() → get all values ✔ entrySet() → get key-value pairs , size() and isEmpty() ✔ Types of Map → HashMap, LinkedHashMap, TreeMap ✔ HashMap → no order , LinkedHashMap → maintains insertion order ✔ TreeMap → sorts keys 🧠 Example Solved: Solved a problem to count the frequency of each character in a string (e.g., Mississippi → M1i4s4p2) using Map. Learned how to efficiently track occurrences using containsKey(), get(), and put() methods. A big thank you to TAP Academy, Harshit T Sir, and Somanna M G Sir for explaining complex concepts in such a simple and practical way. Your teaching style, real-world examples, and constant support have made a huge difference in my understanding of Java and problem-solving. 🙏 #Java #CollectionsFramework #Map #HashMap #LinkedHashMap #DataStructures #CodingJourney #Consistency

🚀 Exploring the Collection Framework in Java Ever wondered how Java efficiently manages large amounts of data? 🤔 Recently, I stepped into the Collection Framework—a powerful concept used for handling data effectively. 🔍 What is the Collection Framework? It is a collection of classes and interfaces that help in storing, manipulating, retrieving, and processing data easily. 💡 Why use it? ✔ Easy to store data ✔ Easy to manipulate ✔ Easy to retrieve ✔ Easy to process 📌 Core Interfaces: • List • Set • Map 🔗 Started with List Interface: Explored implementations like: • ArrayList • LinkedList • ArrayDeque • PriorityQueue 📊 What I analyzed: • Usage • Initial capacity • Heterogeneous data support ➡️ Then explored: • Insertion order • Duplicates • Null handling ➡️ Also looked into: • Constructors • Internal structure • Hierarchy 🔄 Ways to Access Elements: • For loop • For-each loop ➡️ Advanced ways: • Iterator • ListIterator 👉 Key Difference: Iterator moves only forward, whereas ListIterator supports both forward and backward traversal. 🌍 Real-Life Use Case: Imagine building a student management system 📚 • Use ArrayList to store and display student records • Use LinkedList for frequent insertions/deletions • Use PriorityQueue for priority-based processing 💡 Key Takeaway: Choosing the right data structure depends on the use case and performance requirements. 💻 Mini Code Example: import java.util.*; public class Demo { public static void main(String[] args) { List<String> list = new ArrayList<>(); list.add("Java"); list.add("Python"); for(String lang : list) { System.out.println(lang); } } } ✨ Special thanks to Sharath R for the clear and practical explanation! TAP Academy Bibek Singh #Java #Collections #CollectionFramework #ArrayList #LinkedList #DataStructures #OOP #Programming #FullStackDevelopment #LearningJourney #Coding #Developer #TapAcademy

I’m learning Java — and this week I went deep into the Java Collections Framework 🚀 Honestly, this is where coding becomes practical. Here’s what clicked for me 👇 🔹 Collections = How you actually manage data in real projects Instead of arrays, Java gives structured ways to store data: 👉 List 👉 Set 👉 Map Each solves a different problem 🔹 List → Ordered, allows duplicates ✔ ArrayList → fast access (read-heavy) ✔ LinkedList → fast insert/delete 👉 Default choice → ArrayList (most cases) 🔹 Set → No duplicates allowed ✔ HashSet → fastest (no order) ✔ LinkedHashSet → maintains insertion order ✔ TreeSet → sorted data 👉 Use this when uniqueness matters 🔹 Map → Key-Value pairs (most used in real systems) ✔ HashMap → fastest, most common ✔ LinkedHashMap → maintains order ✔ TreeMap → sorted keys 👉 Example: storing userId → userData 🔹 Iteration styles (very important in interviews) ✔ for-each → clean & simple ✔ Iterator → when removing elements ✔ forEach + lambda → modern Java 🔹 Streams API → Game changer 🔥 Instead of loops: 👉 filter → select data 👉 map → transform 👉 collect → store result Example flow: filter → map → sort → collect This makes code: ✔ cleaner ✔ shorter ✔ more readable 💡 Big realization: Choosing the wrong collection can silently affect performance (O(1) vs O(n) vs O(log n)) 📌 Best practices I noted: ✔ Use interfaces (List, not ArrayList) ✔ Use HashMap by default ✔ Use Streams for transformation ✔ Avoid unnecessary mutations 🤔 Curious question for you: In real projects, 👉 When do you actually choose LinkedList over ArrayList? I’ve rarely seen it used — would love real-world scenarios 👇 #Java #JavaCollections #JavaDeveloper #LearningInPublic #SoftwareDevelopment #CodingJourney

Day 11/100 – Java Practice Challenge 🚀 Continuing my #100DaysOfCode journey with another important Java concept. 🔹 Topic Covered: Compile-time vs Runtime Polymorphism 💻 Practice Code: 🔸 Compile-time Polymorphism (Method Overloading) class Calculator { int add(int a, int b) { return a + b; } int add(int a, int b, int c) { return a + b + c; } } 🔸 Runtime Polymorphism (Method Overriding) class Animal { void sound() { System.out.println("Animal sound"); } } class Cat extends Animal { @Override void sound() { System.out.println("Cat meows"); } } public class Main { public static void main(String[] args) { // Compile-time Calculator c = new Calculator(); System.out.println(c.add(10, 20)); System.out.println(c.add(10, 20, 30)); // Runtime Animal a = new Cat(); a.sound(); } } 📌 Key Learnings: ✔️ Compile-time → method decided at compile time ✔️ Runtime → method decided at runtime ✔️ Overloading vs Overriding difference 🎯 Focus: Understanding how Java resolves method calls 🔥 Interview Insight: Difference between compile-time and runtime polymorphism is one of the most frequently asked Java interview questions. #Java #100DaysOfCode #MethodOverloading #MethodOverriding #Polymorphism #JavaDeveloper #Programming #LearningInPublic

Day 62 of Sharing What I’ve Learned🚀 Iterator in Java — Safe and Efficient Traversal After understanding how collections store and organize data, I revisited an important concept — how to safely traverse them using Iterator. 👉 Accessing data is easy… but doing it correctly and safely matters more. 🔹 What is an Iterator? Iterator is an interface in Java used to traverse elements of a collection one by one. 👉 It provides a standard way to loop through: ArrayList HashSet LinkedList And more… 🔹 Why not just use a for loop? Using a normal loop works… but it has limitations: ❌ Not safe when modifying collection ❌ Can lead to ConcurrentModificationException ❌ Not universal for all collection types 👉 That’s where Iterator comes in ✔ 🔹 Key Methods of Iterator hasNext() → checks if next element exists next() → returns the next element remove() → removes the current element safely 🔹 Example import java.util.*; public class Main { public static void main(String[] args) { ArrayList<String> list = new ArrayList<>(); list.add("Java"); list.add("Python"); list.add("C++"); Iterator<String> it = list.iterator(); while(it.hasNext()) { String lang = it.next(); System.out.println(lang); } } } 🔹 Real Advantage 💡 👉 Removing elements while iterating: Iterator<String> it = list.iterator(); while(it.hasNext()) { if(it.next().equals("Python")) { it.remove(); // Safe removal } } ✔ No errors ✔ Clean logic ✔ Interview-friendly concept 🔹 Day 62 Realization Traversing data is not just about loops — it’s about doing it safely and efficiently. 👉 Iterator provides better control and prevents runtime issues 👉 Essential when working with dynamic collections #Java #Collections #DataStructures #CollectionsFramework #Iterator #Programming #DeveloperJourney #100DaysOfCode #Day61 Grateful for guidance from, TAP Academy Sharath R kshitij kenganavar

🗂️ Java Collections Framework When I first started Java, I just used ArrayList everywhere. 😅 Need a list? ArrayList. Need to store data? ArrayList. Need anything? ArrayList. Sound familiar? Then I discovered there's an entire UNIVERSE of data structures in Java — each built for a specific purpose. ━━━━━━━━━━━━━━━━━━━━━━ 🏗️ The Big Picture — Collections Hierarchy ━━━━━━━━━━━━━━━━━━━━━━ Java Collections has TWO separate hierarchies: 1️⃣ Collection (Iterable → Collection → List / Set / Queue) 2️⃣ Map (completely separate — Key-Value pairs) 📌 Collection Side: ▸ List → ordered, duplicates allowed   → ArrayList, LinkedList, Vector, Stack ▸ Set → no duplicates   → HashSet, LinkedHashSet, TreeSet ▸ Queue / Deque → FIFO / double-ended   → PriorityQueue, ArrayDeque 📌 Map Side: ▸ HashMap → fast, unordered ▸ LinkedHashMap → insertion-order maintained ▸ TreeMap → sorted by keys ▸ Hashtable → legacy (avoid in new code) ━━━━━━━━━━━━━━━━━━━━━━ 🔑 The Golden Rule: ━━━━━━━━━━━━━━━━━━━━━━ Choosing the WRONG collection = slow code. Choosing the RIGHT collection = clean, efficient code. And that's exactly what this series is about. 🎯 📌 What's coming next in this series: ✅ ArrayList vs LinkedList — when does it actually matter? ✅ HashSet vs TreeSet — hashing vs sorting ✅ HashMap vs TreeMap vs LinkedHashMap ✅ Queue, Deque & PriorityQueue with real use cases ✅ Interview questions on Collections ━━━━━━━━━━━━━━━━━━━━━━ If you followed my OOPs series — this one is going to be even better. 🚀 Drop a 🙋 in the comments if you're in for this series!TAP Academy #Java #Collections #JavaDeveloper #Programming #DSA #100DaysOfCode #JavaSeries #SoftwareEngineering #LearningInPublic #LinkedInLearning#tapacademy