Inheritance

Introduction

The process by which one class acquires the properties (data members) and functionalities (methods) of another class is called inheritance. The aim of inheritance is to provide the reusability of code so that a class has to write only the unique features, and the rest of the common properties and functionalities can be extended from the other class.

Lab Overview

In this lab, we will explore and demonstrate Java Inheritance.

Learning Objective

By the end of this lab, Learners will be able to use Inheritance in Java.

Instructions

Child Class

The class that extends the features of another class is known as a child class, subclass, or derived class.

Parent Class

The class whose properties and functionalities are used (inherited) by another class is known as the parent class, superclass, or base class.

Begin

In this lab, we have a base class, “Doctor,” and a subclass, “Surgeon.”

Step 1: Create a Java project named “inheritanceDemo.”

Step 2: Create a class named Doctor, and add the code below.

public class Doctor {
   String DoctorName;
   String Department;
  public void Doctor_Details() {
       System.out.println("Doctor Details...");
   }
}

Step 3: Create a class named Surgeon, and add the code below.

public class Surgeon extends Doctor {
   void Surgeon_Details() {
       System.out.println("Surgeon  Detail...");
       System.out.println(Department = "Cardio");
   }
}

Step 4: Create a class named Hospital. In this class, we will create a main() method.

public class Hospital {
   public static void main(String args[]) {
       Surgeon s = new Surgeon();
       s.Doctor_Details();
       s.Surgeon_Details();
   }
}

The project hierarchy will look like this:

inheritanceDemo/
├── Doctor.java
├── Hospital.java
└── Surgeon.java

Step 5: Run your Java Project.

Output on Console:

Doctor Details...

Surgeon Detail...

Cardio

Based on the above example, we can say that Surgeon IS-A Doctor. This means a child class has an IS-A relationship with the parent class. This inheritance is known as the IS-A relationship between the child and parent class.

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GLAB - 303.9.2 Basic Inheritance Example.zip

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