Java OOP Fundamentals: Classes, Inheritance, and Polymorphism

Classes and Objects

public class Car {
    private String model;
    private int year;
    
    public Car(String model, int year) {
        this.model = model;
        this.year = year;
    }
    
    public void start() {
        System.out.println(model + " is starting...");
    }
}

Inheritance

public class ElectricCar extends Car {
    private int batteryRange;
    
    public ElectricCar(String model, int year, int range) {
        super(model, year);
        this.batteryRange = range;
    }
    
    @Override
    public void start() {
        System.out.println("Electric motor activated");
    }
}

Polymorphism

Car myCar = new ElectricCar("Tesla", 2024, 350);
myCar.start(); // "Electric motor activated"