Core Java Collections Framework Notes

Day 43-What I Learned In a Day(JAVA) Today I worked on String concepts in Java and practiced some interesting problems. What I learned: Creating and using strings in Java Converting a number into an array using strings Handling characters using charAt() Problems I practiced: ✅ Created and manipulated strings ✅ Converted number -array using string ✅ Moved zeros to the end of an array These problems helped me understand how strings and arrays work together and improved my problem-solving skills. Learning step by step and getting better every day! Practiced 👇 #Java #CodingPractice #LearningJourney #Programming #100DaysOfCode

🚀 I thought I knew Java Arrays… until I actually revised them properly. Most beginners memorize syntax like: int[] arr = new int[5]; But interviews don’t test syntax. They test understanding. Here’s what actually matters: • Why array index starts from 0 • How memory is allocated internally • Why arrays are fixed size • Why O(1) access time makes arrays powerful • When to use Array vs ArrayList If your array basics are weak, Data Structures will feel difficult. Today I revised: ✔ Declaration & Initialization ✔ 2D and Jagged Arrays ✔ Traversal methods ✔ Arrays utility methods Strong fundamentals > Fancy topics. Are your array basics really strong? #Java #DSA #Programming #JavaDeveloper #CodingJourney

🚀 New YouTube Video Alert! I just uploaded a new video where I practice Java loops by building a Multiplication Table Exercise 🧮 In this tutorial, I explain and demonstrate how to use: 🔹 "for" loop 🔹 "while" loop We go step by step to understand how iteration works in Java and how loops can simplify repetitive tasks. 💡 This exercise is perfect for beginners who want to strengthen their logic and improve their programming skills. 📺 Watch the full video here: [https://lnkd.in/dPqCz2h8] Let’s keep learning and building strong programming fundamentals together 💻🔥 #Java #Programming #Loops #Coding #YouTube #SoftwareDevelopment #LearnToCode

Day 21– Thread Methods in Java Today I explored how to control threads in Java using different methods. Things I learned: 🔹 start() – begins thread execution 🔹 run() – contains logic (called internally) 🔹 sleep() – pauses thread for a specific time 🔹 join() – ensures one thread finishes before another starts 💡 Key takeaway: Thread methods help manage execution flow and improve control over multithreading behavior. Step by step understanding how Java handles concurrent tasks 🚀 #Java #Multithreading #Threads #Programming #LearningInPublic #Day21 #100DaysOfJava

💻 Day 23 – Strings in Java Today I explored Strings in Java, one of the most fundamental and important concepts. I learned about different types of string handling: 🔹 String – Immutable (cannot be changed) 🔹 StringBuilder – Mutable and faster 🔹 StringBuffer – Mutable and thread-safe Understanding immutability was a key highlight today, as it plays an important role in memory management and performance. 💡 Key takeaway: Choosing the right type of string handling improves both performance and efficiency in Java applications. Continuing to strengthen my core Java concepts step by step 🚀 #Java #Strings #Programming #LearningInPublic #CodingJourney #Day23

☕ Learn Java with Me — Day 9 Text is everywhere in programming. Today we learned something simple, but extremely powerful. 👉 Strings in Java Strings are used to store text values. For example:String name = "Java"; Simple. But this is where real applications begin. With Strings, we can:→ store names → messages → email IDs → user inputs → passwords We also explored some useful methods:→ length() → toUpperCase() → toLowerCase() → equals() This made Java feel much more practical. Because every real-world application works with text. From numbers → real user interaction 🚀 We’re learning together 🤝 #java #coding #strings #learning #showup

Day 49-What I Learned In a Day (JAVA) Today, I focused on understanding the execution flow of static elements in Java. 🔹 Learned about: • Static variables and how they are shared across objects • Static methods and how they can be accessed without object creation • Static initializer (single-line) • Static initializer (multi-line) This helped me clearly understand how Java handles memory and execution at the class level before objects are created. Building strong fundamentals step by step! #Java #Programming #LearningJourney #OOP #TechSkills

Day 55-What I Learned In a Day (JAVA) Today, I learned how to create and use constructors in Java. 🔹 A constructor is a special method used to initialize an object when it is created. 🔹 Constructors are non-static by default, meaning they work with objects and help assign values to instance variables. 🔹 They are automatically executed when an object is created, making object initialization simple and efficient. 🔹 This reduces the need for setting values manually after object creation. Understanding constructors helped me see how Java initializes objects in a structured and efficient way. #Java #OOP #Constructors #LearningJourney #Programming #TechSkills

Day 45-What I Learned In a Day (JAVA) Today I explored some important concepts related to static in Java: 🔹 Static Method Learned how static methods belong to the class and can be called without creating an object. 🔹 Static Initializer (Static Block) Understood how a static block is executed only once when the class is loaded. 🔹 Single-Line Static Initializer Explored how we can initialize static variables in a single line. 🔹 Multi-Line Static Initializer Learned how to use static blocks for complex initialization logic. Practiced 👇 #Java #Programming #LearningJourney #Coding #100DaysOfCode

Day 44-What I Learned In a Day(JAVA) Today I revised pattern programming in Java to strengthen my core logic and understanding of loops. What I practiced: • Star patterns • Number patterns • Pyramid patterns • Inverted patterns • Nested loop logic Pattern programming helped me improve: • Loop control (for/while) • Logical thinking • Understanding of rows & columns Every pattern I solve makes my logic stronger step by step. Consistency is the key #Java #CodingJourney #PatternProgramming #Learning #StudentDeveloper