Partial abstraction in Java - Mini Project: Build & Apply

Partial Abstraction in Java

📖 Scenario: You are creating a simple program to represent different types of vehicles. Some vehicles share common features, but each type has its own way of showing details.

🎯 Goal: Build a Java program using partial abstraction with an abstract class and concrete subclasses to show vehicle details.

📋 What You'll Learn

Create an abstract class called Vehicle with one abstract method showDetails() and one concrete method start().

Create two subclasses called Car and Bike that extend Vehicle.

Implement the showDetails() method in both subclasses with specific messages.

Create objects of Car and Bike and call their start() and showDetails() methods.

💡 Why This Matters

🌍 Real World

Partial abstraction is used in software to define common behavior for a group of related objects while allowing each object to have its own specific details.

💼 Career

Understanding partial abstraction helps in designing clean, reusable code in object-oriented programming, which is essential for many software development jobs.

1

Create the abstract class Vehicle

Create an abstract class called Vehicle with one abstract method showDetails() and one concrete method start() that prints "Vehicle is starting".

Java

abstract class Vehicle {
    // Your code here
}

Need a hint?

Use the abstract keyword for the class and the method showDetails(). The method start() should print the message.

2

Create subclasses Car and Bike

Create two classes called Car and Bike that extend the abstract class Vehicle.

Java

abstract class Vehicle {
    abstract void showDetails();
    void start() {
        System.out.println("Vehicle is starting");
    }
}

// Your code here

Need a hint?

Use extends Vehicle to inherit. Implement the showDetails() method in both classes with the exact print statements.

3

Create objects and call methods

In the main method, create one object of Car called myCar and one object of Bike called myBike. Call the start() and showDetails() methods on both objects.

Java

abstract class Vehicle {
    abstract void showDetails();
    void start() {
        System.out.println("Vehicle is starting");
    }
}

class Car extends Vehicle {
    void showDetails() {
        System.out.println("This is a Car");
    }
}

class Bike extends Vehicle {
    void showDetails() {
        System.out.println("This is a Bike");
    }
}

public class Main {
    public static void main(String[] args) {
        // Your code here
    }
}

Need a hint?

Create objects with new and call the methods exactly as shown.

4

Display the output

Run the program and print the output of the start() and showDetails() methods for both myCar and myBike.

Java

abstract class Vehicle {
    abstract void showDetails();
    void start() {
        System.out.println("Vehicle is starting");
    }
}

class Car extends Vehicle {
    void showDetails() {
        System.out.println("This is a Car");
    }
}

class Bike extends Vehicle {
    void showDetails() {
        System.out.println("This is a Bike");
    }
}

public class Main {
    public static void main(String[] args) {
        Car myCar = new Car();
        Bike myBike = new Bike();
        myCar.start();
        myCar.showDetails();
        myBike.start();
        myBike.showDetails();
    }
    // Output is shown when program runs
}

Need a hint?

Check the console output matches the expected lines exactly.