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How to Convert 2 Classes to Inherit from the Same Abstract Class in Java

Our team is here to guide you through the process of converting two classes to inherit from the same abstract class in Java. In object-oriented programming, this is a fundamental concept that allows you to create a new class based on an existing one, promoting code reusability and maintainability. In Java, you can use abstract classes to define a common structure for multiple classes. Let's dive into the process step by step, ensuring you have a solid understanding of this essential OOP technique.

Inheriting from Abstract Classes

Discover how to enhance code structure and foster reusability in your Java projects. Learn how to convert 2 classes to inherit from the same abstract class in Java, a valuable skill when you need to write your Java assignment efficiently. With step-by-step guidance, you'll gain a deeper understanding of Java's object-oriented principles and create more organized and maintainable code. Whether you're a student looking to excel in your coursework or a developer aiming to streamline your codebase, this guide has you covered.

Step 1: Creating an Abstract Class

The first step in our journey is to create an abstract class that both of your classes will inherit. An abstract class cannot be instantiated but can define abstract methods that must be implemented by its subclasses. Here's an example of the abstract class we'll call `Shape`:

```java abstract class Shape { // Abstract method that must be implemented by subclasses abstract double calculateArea(); // Concrete method shared by all subclasses voidprintShape() { System.out.println("This is a shape."); } } ```


  • We've created an abstract class called `Shape`.
  • Inside `Shape`, we have an abstract method `calculateArea()`, which is meant to be implemented by any concrete subclass.
  • We also have a concrete method `printShape()` that provides a common behavior for all subclasses.

Step 2: Modifying Existing Classes

Our next step is to modify your existing classes to inherit from the `Shape` abstract class and provide implementations for the abstract method `calculateArea()`. Let's take two examples: `Circle` and `Rectangle`.

Circle Class

```java class Circle extends Shape { double radius; Circle(double radius) { this.radius = radius; } @Override doublecalculateArea() { returnMath.PI * radius * radius; } } ```

Rectangle Class

```java class Rectangle extends Shape { double length; double width; Rectangle(double length, double width) { this.length = length; this.width = width; } @Override doublecalculateArea() { return length * width; } } ```


  • We've used the extends keyword to make Circle and Rectangle inherit from the Shape abstract class.
  • In each subclass, we've provided an implementation for the calculateArea() method specific to that shape (circle or rectangle).
  • The constructors in each subclass initialize the specific properties of the shapes.


By following these two steps, you've successfully converted two classes to inherit from the same abstract class in Java. This approach allows you to share common behaviors and ensure a consistent structure in your code, which can lead to more efficient and maintainable software projects. With your classes inheriting from the abstract class Shape, you can now create instances of Circle and Rectangle, each with its specific functionality, while still benefiting from the shared method printShape(), inherited from the abstract class Shape.