Abstract classes in C++ - Mini Project: Build & Apply

Abstract Classes in C++

📖 Scenario: Imagine you are creating a simple program to manage different types of vehicles. Each vehicle can start and stop, but the way they start might be different. We will use abstract classes to define a general vehicle and then create specific types of vehicles.

🎯 Goal: Build a C++ program that uses an abstract class called Vehicle with a pure virtual function start(). Then create two classes, Car and Bike, that inherit from Vehicle and implement the start() method. Finally, create objects of Car and Bike and call their start() methods.

📋 What You'll Learn

Create an abstract class Vehicle with a pure virtual function start()

Create a class Car that inherits from Vehicle and implements start()

Create a class Bike that inherits from Vehicle and implements start()

Create objects of Car and Bike

Call the start() method on both objects and print the output

💡 Why This Matters

🌍 Real World

Abstract classes are used in software design to define common interfaces for different objects, like vehicles, shapes, or devices, ensuring they share certain behaviors.

💼 Career

Understanding abstract classes is important for designing flexible and maintainable code in many programming jobs, especially in object-oriented programming.

1

Create the abstract class Vehicle

Write an abstract class called Vehicle with a pure virtual function start() that returns void.

C++

// Your code here

Need a hint?

Use virtual void start() = 0; inside the class to make it abstract.

2

Create the Car class inheriting Vehicle

Create a class called Car that inherits from Vehicle. Implement the start() method to print "Car started".

C++

class Vehicle {
public:
    virtual void start() = 0; // pure virtual function
};

// Your code here

Need a hint?

Use class Car : public Vehicle and implement start() with std::cout.

3

Create the Bike class inheriting Vehicle

Create a class called Bike that inherits from Vehicle. Implement the start() method to print "Bike started".

C++

class Vehicle {
public:
    virtual void start() = 0; // pure virtual function
};

class Car : public Vehicle {
public:
    void start() override {
        std::cout << "Car started" << std::endl;
    }
};

// Your code here

Need a hint?

Similar to Car, create Bike class and implement start().

4

Create objects and call start()

In the main() function, create an object myCar of type Car and an object myBike of type Bike. Call start() on both objects to print their start messages.

C++

class Vehicle {
public:
    virtual void start() = 0; // pure virtual function
};

class Car : public Vehicle {
public:
    void start() override {
        std::cout << "Car started" << std::endl;
    }
};

class Bike : public Vehicle {
public:
    void start() override {
        std::cout << "Bike started" << std::endl;
    }
};

int main() {
    // Your code here
}

Need a hint?

Create objects myCar and myBike and call start() on each.