#100daysofcodingchallenge - Day34 Question: Write a Java program to find the index of the last occurrence of a given element (k) in an array of integers. If the element is not found, print -1 Input: 8 2 5 6 4 7 9 5 3 5 Output: 6 #100daysofcodingchallenge #codingchallenge #day34 #corejava #ITjobs #freshers #softwarejobs #practicecoding #continuouslearning #learningcoding #problemsolving

🚀 Day 4/30 — Java Challenge Topic: Control Statements in Java Today I revised decision-making and looping statements. Types of Control Statements: ✔ if ✔ if-else ✔ switch ✔ for loop ✔ while loop ✔ do-while loop 💡 Key Learnings: • switch uses break to avoid fall-through • do-while executes at least once • Difference between break and continue • for vs while loops 🎯 Interview Questions: What are control statements? Difference between if and switch? for vs while? break vs continue? while vs do-while? Nested loops? Infinite loop? Fall-through in switch? Can switch use String? When to use switch? Follow my 30-Day Java Challenge for daily Java revision. #Java #JavaDeveloper #BackendDeveloper #LearningInPublic #30DaysChallenge #Freshers #Coding #SoftwareEngineer #JavaBasics

Day 6 of my Java Learning Journey 🚀 Today I focused on understanding how Java interacts with external data: ✔️ File Handling (reading and writing files) ✔️ Basic concepts of database connectivity (JDBC) ✔️ Practiced simple programs to handle file input and output Learning how applications store and retrieve data is an important step toward building real-world software. Taking small steps every day and staying consistent 💻 #Java #LearningJourney #Coding #SoftwareDevelopment #Freshers #Consistency

🚀 Day 26 of Java Practice – Sort 0s and 1s in Array Continuing my Java learning journey, today I solved an important array problem using the two-pointer approach. 💡 Problem: Sort an array of 0s and 1s 👉 Solution: import java.util.*; class MainClass { public static void main(String args[]) { int a[] = {1, 0, 1, 0, 0, 1, 0, 1}; int i = 0; int j = a.length - 1; while(i < j) { if(a[i] == 1 && a[j] == 0) { int temp = a[i]; a[i] = a[j]; a[j] = temp; i++; j--; } else if(a[i] == 0) { i++; } else if(a[j] == 1) { j--; } } for(int num : a) { System.out.print(num + " "); } } } ✅ Output: 0 0 0 0 1 1 1 1 📌 What I learned: ✔ Two-pointer technique ✔ In-place sorting ✔ Optimized O(n) solution Improving problem-solving step by step 🚀 Open to opportunities as a Java Developer (Fresher). #Java #CodingJourney #Day26 #Freshers #OpenToWork

🚀 Day 16 of Java Practice – First Repeating Element in Array Continuing my Java learning journey, today I solved an important array problem frequently asked in interviews. 💡 Problem: Find the first repeating element in an array 👉 Solution: import java.util.*; class MainClass { public static void main(String args[]) { int arr[] = {10, 5, 3, 4, 3, 5, 6}; HashSet<Integer> set = new HashSet<>(); int firstRepeat = -1; for(int i = arr.length - 1; i >= 0; i--) { if(set.contains(arr[i])) { firstRepeat = arr[i]; } else { set.add(arr[i]); } } if(firstRepeat != -1) { System.out.println("First repeating element: " + firstRepeat); } else { System.out.println("No repeating element found"); } } } ✅ Output: 5 📌 What I learned: ✔ Using HashSet for duplicate detection ✔ Reverse traversal technique ✔ Optimized approach for array problems Improving problem-solving step by step 🚀 Open to opportunities as a Java Developer (Fresher). #Java #CodingJourney #Day16 #Freshers #OpenToWork

Every Java Developer should master these 5 basics 👇 1️⃣ OOP Concepts (Encapsulation, Inheritance, Polymorphism) 2️⃣ Collections Framework (List, Set, Map) 3️⃣ Exception Handling 4️⃣ Multithreading Basics 5️⃣ JDBC / Database Connectivity These are not just “theory” — they are the foundation of real-world backend development. What concept do you think is most important for a fresher? #Java #BackendDeveloper #Learning #Fresher #SpringBoot

Struggling to learn Java or need a fast, reliable revision guide? I’ve got you covered. When I first started learning Java, I spent countless hours switching between tutorials, videos, and scattered resources — yet true clarity still felt missing. That’s exactly why I created Java Programming - Complete Notes: A structured, practical, and easy-to-follow resource designed to simplify Java learning from beginner to advanced level. ✔ Covers fundamentals like variables, data types, operators, loops, and control statements ✔ Explains core OOP concepts clearly — classes, objects, inheritance, polymorphism, abstraction ✔ Includes advanced topics like exception handling, multithreading, collections, and more ✔ Designed for quick understanding, revision, and interview preparation Why it’s valuable: 🎯 For Freshers: • Build strong programming fundamentals • Learn Java in a clear, confusion-free way • Prepare effectively for interviews and coding rounds 💼 For Working Professionals: • Revise core Java concepts quickly • Refresh knowledge before interviews or projects • Use it as a practical day-to-day reference Whether you're beginning your coding journey or sharpening your existing skills, structured learning can save you time, boost confidence, and accelerate growth. Learning Java doesn’t have to be overwhelming — it just needs the right roadmap. If you find this helpful, follow me Pulimi Bala sankararao for more content on programming, tech careers, interview prep, and professional growth. #Java #JavaProgramming #Programming #Coding #SoftwareDevelopment #Developers #TechCareers #CareerGrowth #InterviewPreparation #Freshers #Learning #CodingJourney #SoftwareEngineer #LinkedInLearning

🚨 As a fresher, I recently learned something interesting about Java Collections 👇 While working with lists, I encountered a common issue: 👉 ConcurrentModificationException 💥 Problem: List<Integer> list = new ArrayList<>(List.of(1, 2, 3)); for (Integer n : list) { if (n == 3) { list.remove(n); // ❌ Throws ConcurrentModificationException } } 🔍 Why does this happen? Java collections internally use a mechanism called modCount (modification count). When an iterator is created, it stores a snapshot of this value If the list is modified directly (like list.remove()), modCount changes But the iterator’s expected value remains the same 👉 This mismatch leads to ConcurrentModificationException (This is known as Java’s Fail-Fast behavior) ✅ Correct Approach: Use Iterator to safely modify the collection: List<Integer> list = new ArrayList<>(List.of(1, 2, 3)); Iterator<Integer> it = list.iterator(); while (it.hasNext()) { Integer n = it.next(); if (n == 3) { it.remove(); // ✅ Safe removal } } System.out.println(list); // [1, 2] 💡 Key Takeaways: ✔ Don’t modify a collection directly while iterating ✔ Use iterator.remove() for safe updates ✔ Understand Fail-Fast behavior in Java collections ✔ Knowing internals like modCount helps in debugging & interviews ✨ Bonus (Java 8+): list.removeIf(n -> n == 3); Have you faced this issue before? How did you debug it? Let’s discuss 👇 #Java #CoreJava #JavaDeveloper #Programming #Coding #SoftwareDevelopment #Collections #Iterator #ListIterator #JavaCollections #ConcurrentModificationException #FailFast #Debugging #InterviewPreparation #LearnJava #Developers #TechCommunity #Freshers