OOP Learning Roadmap with Tasks (Beginner → Advanced)
Stage 1: Basics of Classes and Objects
Goal: Understand classes and objects.
Tasks: Create a Student class with name and age, then create an object and print the details. Create a Car class with color and speed, then change values using objects. Create a Book class with title, author, price, and display them.
Stage 2: Constructors
Goal: Learn how to initialize objects with constructors.
Tasks: Add a default constructor to Student and create objects. Add a parameterized constructor to Car and initialize objects with color and speed. Create multiple Book objects using parameterized constructor and print their info.
Stage 3: Encapsulation (Getters & Setters)
Goal: Protect object data.
Tasks: Make age private in Student and create getter and setter. Make balance private in BankAccount class and implement deposit/withdraw methods. Restrict marks in Student class to be 0–100 using setters.
Stage 4: Inheritance
Goal: Reuse code and create hierarchies.
Tasks: Create Vehicle class → extend Car and Bike with different speeds/colors. Create Employee → extend Manager and Developer with extra attributes. Override a method in subclass to display details differently.
Stage 5: Polymorphism
Goal: Learn method overloading and overriding.
Tasks: Overload a method calculateArea() for square, rectangle, circle. Override a method display() in Employee subclasses (Manager, Developer). Create an array of Employee objects and call the display() method to see polymorphic behavior.
Stage 6: Abstraction
Goal: Hide unnecessary details.
Tasks: Create an abstract class Shape with abstract method draw() → implement in Circle and Rectangle. Create an interface Drawable → implement in Square and Triangle. Build a mini program where all shapes can draw themselves using abstraction.
Stage 7: Advanced OOP Concepts
Goal: Master static, final, inner classes, and this/super.
Tasks: Create a MathUtil class with static methods (add, subtract, multiply). Use final keyword to prevent overriding in a class/method. Create an inner class in Car called Engine and access it. Use this keyword to distinguish object variables from parameters. Use super keyword to call parent class constructor.
Stage 8: Exception Handling in OOP
Goal: Make objects safer.
Tasks: Handle ArithmeticException in a Calculator class. Handle ArrayIndexOutOfBoundsException while accessing a student array. Create a custom exception InvalidMarkException for invalid student marks.
Stage 9: Collections with OOP
Goal: Store and manage multiple objects.
Tasks: Create an ArrayList of Student objects and display all students. Create a HashMap of Employee ID → Employee object. Filter students with marks > 75 from ArrayList and display them.
Stage 10: Mini OOP Projects
Goal: Integrate all OOP concepts.
Projects: Student Management System Classes: Student, Course Features: Add, display, search students Use ArrayList, encapsulation, inheritance for GraduateStudent Banking System Classes: BankAccount, Savings, Current Features: Deposit, Withdraw, Check balance Exception handling for invalid operations Simple Game Simulation Classes: Player, Enemy, Weapon Features: Display stats, attack, defend Use polymorphism for different enemy types