Java Checked vs Unchecked Exceptions: Understanding the Difference

Understanding the main() Method in Java Every Java program begins execution from a single entry point — the main() method. Understanding its structure is fundamental for anyone starting with Java. public static void main(String[] args) Let’s break it down clearly: public → Access specifier. The JVM must access this method from anywhere. static → Allows the method to be called without creating an object of the class. void → Specifies that the method does not return any value. main → The method name recognized by the JVM as the starting point. String[] args → Command-line arguments passed during program execution. Function Body { } → The block where execution actually begins. If the signature is modified incorrectly, the JVM will not recognize it as the entry point. Understanding this is not just about syntax — it’s about understanding how the JVM interacts with your program. Grateful to my mentor Anand Kumar Buddarapu for emphasizing the importance of fundamentals and ensuring I build a strong base before moving to advanced concepts. Your guidance truly makes a difference. #Java #Programming #CoreJava #LearningJourney #SoftwareDevelopment

📘 Day 8 | Core Java – Revision (Q&A) 🌱 Revising today’s Core Java topics by asking questions and validating my understanding 1. What is an array in Java? ➡️ An array is a collection of elements of the same data type stored in a continuous memory location. 2.What is method overloading? ➡️ Method overloading means defining multiple methods with the same name but different parameters in the same class. It is resolved at compile time. 3.What is method overriding? ➡️ Method overriding occurs when a subclass provides a specific implementation of a method already defined in its parent class. It supports runtime polymorphism. 4. What is the use of the super keyword? ➡️ The super keyword is used to refer to the parent class object, access parent class variables, methods, and constructors. 5.What is method hiding in Java? ➡️ Method hiding happens when a static method in a subclass has the same signature as a static method in the parent class. 6.What is typecasting in Java? ➡️ Typecasting is the process of converting one data type into another. 7.What is an abstract class? ➡️ An abstract class is a class declared using the abstract keyword and may contain abstract and non-abstract methods. 8.What is a concrete class? ➡️ A concrete class is a class that provides implementation for all methods and can be instantiated. 9.What is an interface? ➡️ An interface is a blueprint of a class that contains abstract methods and is used to achieve abstraction and multiple inheritance. 10.What is polymorphism in Java? ➡️ Polymorphism means one method performing different behaviors based on the object type. 11.What are the types of polymorphism? ➡️ Compile-time polymorphism (method overloading) and runtime polymorphism (method overriding). #CoreJava #JavaLearning #LearningJourney #Programming #MCAGraduate

🧠 Is Java’s variable a productivity boost—or a readability trap? 👉 Local Variable Type Inference — friend or foe? The post looks at: ✅ Where variable genuinely improves developer productivity ✅ When it can reduce code clarity ✅ Practical guidelines for using it responsibly in real-world Java codebases If you work with Java and care about clean, maintainable code, this is worth a look. 🔗 Blog link: https://lnkd.in/gsexkzWe #Java #JavaDev #CleanCode #CodeQuality #SoftwareEngineering #Programming #BackendDevelopment #DeveloperProductivity #TechWriting

📘 Day 7 | Core Java – Concept Check🌱 Revising Core Java concepts and validating my understanding with answers 👇 1️⃣ Why does Java not support multiple inheritance with classes? -->To avoid ambiguity and complexity (diamond problem). Java achieves multiple inheritance using interfaces instead. 2️⃣ What happens if we override equals() but not hashCode()? -->It breaks the contract between equals() and hashCode(), causing incorrect behavior in hash-based collections like HashMap. 3️⃣ Can an abstract class have a constructor? Why? --> Yes, an abstract class can have a constructor to initialize common data when a subclass object is created. 4️⃣ Why is method overloading decided at compile time? --> Because it is resolved based on method signature (method name + parameters) at compile time, not at runtime. 5️⃣ What is the difference between method overriding and method hiding? --> Overriding happens with non-static methods at runtime, while hiding happens with static methods at compile time. 6️⃣ Why can’t we create an object of an abstract class? -->Because abstract classes may contain abstract methods without implementation, and objects must have complete behavior. 7️⃣ How does polymorphism help in reducing code dependency? --> It allows programming to interfaces or parent classes, making code flexible and easy to extend without modification. 8️⃣ What is the use of the instanceof operator in Java? --> It checks whether an object belongs to a specific class or interface at runtime. Learning concepts deeply by questioning and validating answers 📚💻 #CoreJava #JavaLearning #ProgrammingConcepts #LearningJourney #MCAGraduate

There is quiet change in Java that every Java Developer should know about👀 I still remember the first Java program I ever wrote like every beginner, I memorized this line like a ritual : `public static void main(String[] args)`   But here’s the surprising part In modern Java (21+), you can now write: void main() {     System.out.println("Hello World"); }   Yes… no `static`. 😮 So what actually changed?   **Old JVM behaviour** When a Java program starts: 1️⃣ JVM loads the class 2️⃣ No objects exist yet 3️⃣ JVM looks for a method it can call directly   Since non-static methods need an object, Java forced us to use a static `main()`. That’s why we all memorized that signature. But in Modern JVM behavior (Java 21 → 25) JVM quietly does this behind the scenes: ```java new Main().main(); ``` It creates the object and calls the method for you.   This change actually pushes Java closer to being more object-oriented, because now your program can start from an instance method instead of a static one.   Next time, let’s discuss a fun debate Why Java is still NOT a 100% Object-Oriented language.   Did you know this change already happened?   #Java #Programming #JVM #SoftwareEngineering #Developers

📘 Java Exception Handling – Complete Guide for Beginners & Professionals 🔗 To get more updates join What's app: https://lnkd.in/dgSMr5_s Exception handling is one of the most important concepts in Java that ensures smooth program execution even when unexpected errors occur. I’ve created this structured cheat sheet to simplify how exceptions work—making it a helpful reference for students, testers, and developers. 🔎 What this guide covers: ✅ What is an Exception? An abnormal event that disrupts the normal flow of a program. Common examples include: • NullPointerException • ArithmeticException • ClassCastException • ArrayIndexOutOfBoundsException …and more. ✅ Types of Exceptions 📌 Checked Exceptions – Handled at compile time Examples: IOException, SQLException, ClassNotFoundException 📌 Unchecked Exceptions – Occur at runtime and are not checked by the compiler Examples: NullPointerException, ArithmeticException ✅ Exception Hierarchy A clear flow from Throwable → Exception & Error → Runtime & Checked Exceptions, helping you understand how Java manages failures internally. Perfect for quick revision, interview preparation, and strengthening core Java fundamentals. 💾 Save this for later 🚀 Share it with someone learning Java #Java #ExceptionHandling #CoreJava #Programming #Developers #InterviewPreparation #Coding #TechLearning

It only takes a few lines of code to realize Java’s parameter passing isn’t as obvious as it first looks. Primitives behave one way, immutable objects another, and mutable objects can surprise you if you’re not paying attention to what’s actually being copied. If you’ve ever looked at a method call and wondered why the caller’s data changed, or didn’t, this article breaks down exactly what’s happening in the JVM. https://bit.ly/3OdJYV5

🔹 Local Variable Type Inference in Java (var) Java has always been known for being verbose but explicit. With Local Variable Type Inference, Java became a bit more developer-friendly ✨ 👉 What does it mean? Local Variable Type Inference allows Java to automatically infer the data type of a local variable at compile time. Instead of writing the full type, you write: “Java, you figure it out.” ✅ Why was it introduced? To reduce boilerplate code To improve readability To make Java feel more modern, without losing type safety ⚠️ Important rules to remember var is not dynamic typing (Java is still strongly typed) Works only for local variables The variable must be initialized Not allowed for: Class fields Method parameters Return types 💡 Best practice Use var when: The type is obvious from the right side It improves clarity, not confusion Avoid it when: It hides important domain meaning It hurts readability for others 💬 Java is evolving, but its core principles stay strong. Clean code > Short code. #Java #JavaDeveloper #CleanCode #Programming #BackendDevelopment #LearningInPublic

🚀 Day 5 – Core Java | How a Java Program Actually Executes Good afternoon everyone. Today’s session answered a question most students never ask — 👉 Why do we write public static void main the way we do? 🔑 What we clearly understood today: ✔ Revision of OOP fundamentals → Object, Class, State & Behavior ✔ Why a Java program will NOT execute without main → main is the entry point & exit point of execution ✔ Role of Operating System OS gives Control of Execution Control is always given to the main method ✔ Why main must be: public → visible to OS static → accessed without object creation void → no return value ✔ Why Java code must be inside a class OS → JVM → Class → Main Method ✔ Complete Java Execution Flow .java (High-Level Code) → javac → .class (Bytecode) → JVM → Machine Code → Output ✔ Important Interview Concept A class file is NOT a Java class A class file contains the bytecode of a Java program ✔ Why bytecode is secure Not fully human-readable Not directly machine-executable ✔ Hands-on understanding of: javac Demo.java java Demo Why .class is not written while executing ✔ Difference between: Compiler errors (syntax) Runtime errors (execution) ✔ Why IDEs exist Notepad = Text editor ❌ Eclipse = Java-focused IDE ✅ ✔ Introduction to AI-powered code editors Productivity ↑ Fundamentals still mandatory 💯 💡 Biggest Takeaway: Don’t memorize syntax. Understand what happens inside RAM, Hard Disk, JVM, and OS. This is the difference between ❌ Someone who writes code ✅ A real Java Developer From here onwards, everything will be taught from a memory & execution perspective 🚀 #CoreJava #JavaExecution #MainMethod #JVM #Bytecode #JavaInterview #LearningJourney #DeveloperMindset

Learn how to use the super keyword in Java to access parent class fields, methods, and constructors for clear, maintainable code.