Installation and Configuration
Programming Methodology

Inheritance

In this exercise, you will learn the concept of **Inheritance** in Java, a fundamental pillar of **object-oriented programming**. You will explore how to use base and derived classes to reuse code, allowing you to extend functionality and improve the structure of your code. Through practical examples, you will learn how to override methods, invoke base class methods, and understand how Inheritance facilitates the creation of class hierarchies, promoting reuse and efficient code organization.

Topic

Object-Oriented Programming (OOP)

Java Exercise

In this exercise, you will create a Java program that defines a base class named Animal with common attributes such as name and age, and methods for accessing these attributes. You will then create a derived class named Dog that inherits from the Animal class and overrides the makeSound() method to provide a dog-specific implementation. The goal is to understand how inheritance allows you to reuse code and extend the functionality of classes in Java.

Instructions:

  1. Create a base class named Animal with the attributes name and age, and getters and setters methods for these attributes.
  2. Create a derived class named Dog that inherits from the Animal class and overrides the makeSound() method to make it play a dog-specific sound, such as "Woof!".
  3. In the main method, create an object of the Dog class, set its name and age, and call the makeSound() method to demonstrate the behavior. Overridden.

This exercise will help you understand how to **inherit** functionality from a base class to a derived class, how to override methods, and how to use inheritance to promote code reuse in Java.


public class Animal {
    // Common attributes
    private String name;
    private int age;

    // Constructor
    public Animal(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // Getters and Setters
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    // Method to be overridden
    public void makeSound() {
        System.out.println("The animal makes a sound.");
    }
}

public class Dog extends Animal {
    // Constructor that inherits from Animal
    public Dog(String name, int age) {
        super(name, age);
    }

    // Override the makeSound method
    @Override
    public void makeSound() {
        System.out.println("Woof!");
    }

    public static void main(String[] args) {
        // Create an object of the Dog class
        Dog dog = new Dog("Rex", 5);

        // Display the dog's details
        System.out.println("Name: " + dog.getName());
        System.out.println("Age: " + dog.getAge() + " years");

        // Call the overridden method
        dog.makeSound();
    }
}

 Output:

Name: Rex
Age: 5 years old
Wow!

This program shows how to inherit functionality from a base class to a derived class, and how to override methods to customize the behavior of a derived class in Java. This concept of inheritance is key in object-oriented programming for reusing and extending code.


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