Java Arrays Class Sort Methods

🚀 Day 14 – Array vs ArrayList in Java (Key Differences & Why Arrays Still Matter) Why learn Array when we already have ArrayList? 🤔 At first I thought: “Why bother learning arrays when ArrayList exists?” But the truth is… 👉 You can’t master ArrayList without mastering Array first. Understanding data structures is a must for writing efficient Java programs. Today I compared Array and ArrayList and learned why arrays are still very important. 🧠 Why Array is Important? ✅ Foundation of all data structures ✅ Used internally by ArrayList, HashMap, etc. ✅ Faster access (O(1)) ✅ Less memory usage ✅ Works with primitive types (int, double, etc.) ✅ Best choice for performance-critical code 💡 When to use what? ✔ Use Array → When size is fixed & performance matters ✔ Use ArrayList → When size changes frequently & flexibility is needed 🔥 Final Thought Master arrays first. Advanced collections become easy automatically. #Day14 #Java #Array #ArrayList #DSA #JavaDeveloper #LearningJourney #ProgrammingBasics #Consistency

🚀Day 20 of #120DaysOfCode 📌 Problem: Reverse Integer(7) 📌 Language: Java Algorithm: 1. Initialize rev = 0 2. While x != 0 . Extract digit . Check overflow . Update rev 3. Return rev ⏱️ Time and Space Complexity Time Complexity: O(logn) Space complexity: O(1) 🔥One problem closer to mastery #120DaysOfCode #Day20 #Java #Array #Leetcode #ProblemSolving #Consistency #LearningEveryday #LearningPublic #DSA

🚀 Day 29 | #100Days100ProgrammingChallenge #Language: Java * Concept: Sorting Algorithm – Selection Sort #Today, I implemented Selection Sort using Java 🧑💻✨ #What the program does: * Takes number of elements from the user * Accepts array elements using Scanner * Sorts the array using Selection Sort algorithm * Displays the sorted array in ascending order #Key learnings today: * Better understanding of nested for loops * How Selection Sort works step-by-step * Swapping elements using a temporary variable * Improved logic-building skills #Sample Output: Input : 12 13 22 123 3 Output : 3 12 13 22 123 * Consistency is the key. Moving forward to Day 30 🚀 #Day29 #Java #SelectionSort #DSA #LearningJava #100DaysOfCode #ProgrammingChallenge

A clean visualization of how Java handles Arrays: Syntax: int[] arr = new int[5]; Structure: Contiguous memory locations. Access: Fast retrieval using index numbers. Simple, efficient, and essential for every Java developer. #Java #Programming #CodeNewbie #DeveloperResources

📘 Day 15 | Core Java Series Java has primitive data types, but collections work only with objects. That’s where Wrapper Classes come in 👇 This visual explains: 👉 Primitive vs Wrapper mapping   👉 Why wrapper classes are needed  Remember this: Primitive → value   Wrapper → object  Once this is clear, collections and autoboxing make much more sense. 📌 Save this for revision 💬 Feedback is welcome #Java #CoreJava #LearningInPublic #JavaBasics #Programming

Today I learned the Two Pointer technique in Java. It helped me understand how to solve certain array problems more efficiently by using two indexes instead of nested loops. I practiced it on a simple problem: checking whether a sorted array contains two numbers whose sum equals a target value. This technique: improves time complexity avoids unnecessary loops works well with sorted data. #Java #DSA #TwoPointers #Learning #ProblemSolving

🚀Day 14 of #120DaysOfCode 📌 Problem: Matrix Reshape(566) 📌 Language: Java 🔍Approach 1. Check if Reshape is possible 2. Traverse the original matrix in row order 3. Mapping logic ⏱️ Time and Space Complexity Time Complexity: O(m x n) Space complexity: O(r x c) 🔥One problem closer to mastery #120DaysOfCode #Day14 #Java #Array #Leetcode #ProblemSolving #Consistency #LearningEveryday #LearningPublic #DSA

📘 Core #Java Deep Dive – Foundations That Matter Core #Java provides the fundamental building blocks that form the backbone of real-world Java applications. These concepts define runtime behavior, memory management, and essential #OOP principles Key Concepts: ✅ Object & Class Class ✅ System Class ✅ Strings (String, StringBuffer, StringBuilder) ✅ Arrays ✅ Boxing & Unboxing ✅ Varargs ✅ format() & printf() ✅ Inheritance & Access Modifiers ✅ Method Overriding ✅ Constructor Chaining ✅ Type Casting ✅ instanceof 💡 Understanding these concepts is essential for writing robust, maintainable, and efficient #Javaprograms. 📂 Notes with code examples: 👉 https://lnkd.in/geV_JueJ #CoreJava #JavaProgramming #SoftwareEngineering #OOP #BackendDevelopment #DeveloperCommunity #Programming #TechLearning #JavaDeveloper #Coding

🚀Day 6 of #120DaysOfCode 📌 Problem: Third Maximum number(414) 📌 Language: Java 🔍Approach . Duplicates must be ignored . Sorting is easy but not optimal . We only need top 3 distinct values 🔥 Approaches Maintain three variable . max1 --> largest . max2 --> second largest . max3 --> third largest ⏱️ Time and Space Complexity Time Complexity: O(n) Space complexity: O(1) 🔥One problem closer to mastery #120DaysOfCode #Day6 #Java #Array #Leetcode #ProblemSolving #Consistency #LearningEveryday #LearningPublic #DSA

--- For Loop in Java The for loop is used when the number of iterations is known in advance. It helps execute a block of code repeatedly in a controlled and readable way. Structure of a for loop: Initialization → Condition → Update Example: public class Main { public static void main(String[] args) { for (int i = 1; i <= 5; i++) { System.out.println(i); } } } This loop prints numbers from 1 to 5 by initializing a counter, checking the condition, and updating the counter after each iteration. Why for loops are important: • Useful for iterating over arrays and strings • Commonly used in DSA problems • Helps write concise and readable code Understanding loops is essential for problem-solving and building logical thinking in programming. #Java #ForLoop #DSA #ProgrammingBasics #ControlFlow #SoftwareEngineering