Java OOP Practice: Notification System with Inheritance and Polymorphism

Day 22/100 – Revisiting OOP Concepts in Java ☕💻 Today I went back to the core pillars of Object-Oriented Programming: ✔ Abstraction ✔ Encapsulation ✔ Inheritance ✔ Polymorphism ✔ Association ✔ Aggregation ✔ Composition ✔ Coupling ✔ Cohesion Sometimes we rush into frameworks and advanced topics, but strong fundamentals make everything easier to understand — from backend architecture to scalable system design. Revisiting OOP reminds me that clean structure, low coupling, and high cohesion aren’t just theory… they shape real-world applications. Consistency > Intensity. Still building. 🚀 #100DaysOfCode #Java #OOPS #SoftwareEngineering #CleanCode #Consistency #ComputerScience #LearningJourney

💻 Day 9 — Java OOP Journey Today’s focus: Encapsulation Encapsulation = wrapping data (variables) + methods together and restricting direct access. What I learned: • Make variables private • Use public getters and setters to access them • Can add validation in setters • Keeps data safe and maintainable Example in practice: controlling a student’s name and age through methods, not directly. OOP isn’t just about writing classes — it’s about writing secure, structured, and scalable code. #Java #OOP #Encapsulation #Day9 #LearningInPublic #CodingJourney #ComputerScience

Day 10 of 100 days |💻 Today I learned about Inheritance — how one class can inherit properties from another. 👨👦 Parent Class (Super Class) The class that gives properties. 👶 Child Class (Sub Class) The class that inherits and can add its own features. I also understood: 🔹 this() → refers to the current class 🔹 super() → refers to the parent class And something interesting — Java does NOT support multiple inheritance with classes Because it can cause ambiguity (Diamond Problem) Also explored: ✔ Single-level inheritance ✔ Multi-level inheritance It’s cool how Java lets you reuse code instead of rewriting everything again and again. OOP is slowly starting to make sense #Java #JavaLearning #OOP #Inheritance #ProgrammingJourney #100DaysOfCode #CodingLife #SoftwareDevelopment #TechLearning

💻 Day 10 – Understanding Abstraction in Java Today I explored one of the core pillars of Object-Oriented Programming: Abstraction. Abstraction is about hiding implementation details and showing only the essential features of an object. What I learned today: • How to create an abstract class • Difference between abstract methods and normal methods • How child classes implement abstract methods • How interfaces work in Java • Real-world understanding of “what to do” vs “how to do” Key takeaway: Encapsulation hides data Abstraction hides implementation Using abstract classes and interfaces makes code: ✔ More scalable ✔ More structured ✔ Easier to maintain Every day I’m understanding how OOP concepts make real-world applications more organized and powerful 💡 #Java #OOP #Abstraction #LearningInPublic #ComputerScience #Day10 #CodingJourney

Quick concept of OOP 👨💻 🔁 Polymorphism (Method Overloading) – Same method name but different parameters (type/number/order). It allows one action to behave differently based on input at compile time. Improves readability and flexibility of code 🚀 #Java #OOP #Polymorphism #MethodOverloading #Coding

Hello LinkedIn! Today I learned about Polymorphism, one of the core pillars of Object-Oriented Programming in Java. 📌 What I understood: ✅ Polymorphism means “many forms” ✅ One method can behave differently in different situations ✅ Types of Polymorphism:  • Compile-time (Method Overloading)  • Run-time (Method Overriding) ✅ Helps in writing flexible and scalable code Polymorphism allows us to design systems that are more dynamic and reusable. Step by step, strengthening my OOP concepts and Java fundamentals 💻🔥 Consistency + Practice = Growth 🚀 #Java #OOP #Polymorphism #Programming #LearningJourney #Developer

Day 11 of 100 days 💻 Today I learned about Method Overriding in Java. Method overriding happens when a child class provides its own implementation of a method that is already defined in the parent class. ✔ Same method name ✔ Same parameters ✔ Same return type ✔ Happens in inheritance It helps achieve Runtime Polymorphism — meaning the method that gets executed is decided at runtime. Also learned: 🔹 @Override annotation makes code safer 🔹 Access modifier cannot be more restrictive than the parent method 🔹 final and static methods cannot be overridden OOP concepts are slowly connecting together now — inheritance + polymorphism makes much more sense #Java #JavaLearning #OOP #MethodOverriding #Polymorphism #100DaysOfCode #ProgrammingJourney #SoftwareDevelopment #CodingLife

Day 22/30 Understanding the Power of Polymorphism in Java 💡 Polymorphism is one of the core pillars of Object-Oriented Programming, enabling developers to write flexible, reusable, and maintainable code. This visual highlights some key advantages of polymorphism: 🔹 Increased Flexibility – A parent class reference can point to different subclass objects, allowing dynamic behavior at runtime. 🔹 Code Reusability – Through method overriding and method overloading, developers can reuse logic while adapting behavior. 🔹 Consistent Interface – Different classes can implement the same method structure, making systems easier to understand and use. 🔹 Reduced Complexity – Using the same method name with different parameters simplifies code readability. 🔹 Easier Debugging – Fewer method names and clear logical flow make debugging more efficient. 🔹 Support for Design Patterns – Many patterns like Strategy and Factory rely on polymorphism for flexible design. 🔹 Better Maintainability – Changes in child classes do not affect the overall system structure, helping build scalable applications. Mastering concepts like polymorphism is essential for building robust, scalable, and production-ready software systems. Always remember: 👉 Write code that is not just functional, but also flexible and maintainable. #Java #OOP #Polymorphism #SoftwareDevelopment #Programming #JavaDeveloper #Coding #TechLearning #ObjectOrientedProgramming #SoftwareEngineering #DeveloperCommunity #CodeNewbie #LearnToCode #TechCareers #ProgrammingConcepts

🚀 Understanding Objects in Java – The Foundation of OOP An Object is an instance of a class. It represents real-world entities in programming and is created using the new keyword. 🔹 What does an Object consist of? ✔️ State – Represents data (variables) ✔️ Behavior – Represents functionality (methods) ✔️ Identity – Represents uniqueness 🔹 Ways to Create an Object in Java: 1️⃣ Using new keyword 2️⃣ Using clone() method 3️⃣ Using Class.forName() 4️⃣ Using Deserialization Understanding objects is the first step toward mastering Object-Oriented Programming (OOP) concepts like encapsulation, inheritance, and polymorphism. 💡 Strong fundamentals build strong developers! If you're learning Java or brushing up your basics, keep exploring and practicing daily. #Java #JavaDeveloper #Programming #Coding #SoftwareDevelopment #ObjectOrientedProgramming #OOP #LearnToCode #Developers #TechEducation #ComputerScience #BackendDevelopment #FullStackDeveloper #CodingLife #Programmer #ITCareers #Engineering #100DaysOfCode #CodingJourney #TechCommunity

✨DAY-13: 🔁 Polymorphism in Java – Same Method, Different Behavior! This image perfectly explains one of the most powerful concepts in OOP — Polymorphism 👇 🐾 Base Class: Animal() 🐶 Derived Classes: Dog() and Cat() The programmer simply says: 👉 “Objects, do your thing!” 😎 And what happens? 🐕 Dog responds: “Woof! Woof!” 🐈 Cat responds: “Meow!” Same method call. Different outputs. That’s the beauty of runtime polymorphism (method overriding) in Java. 💡 Technical Insight: When we use a parent class reference like: Animal obj = new Dog(); obj.sound(); Java decides at runtime which method to execute. This is called Dynamic Method Dispatch. 📌 Why Polymorphism Matters: Increases flexibility Improves scalability Promotes clean and maintainable code Follows the “program to interface, not implementation” principle In simple terms: You give the same command… But each object responds in its own way. That’s real-world programming power. 💻🔥 #Java #OOP #Polymorphism #Programming #SoftwareDevelopment #CodingLife #TechConcepts