Why polymorphism is needed in C++ - See It in Action

Why polymorphism is needed

📖 Scenario: Imagine you are building a simple program to manage different types of animals in a zoo. Each animal can make a sound, but the sound is different for each animal. You want to write code that can handle any animal and make it produce its sound without knowing exactly which animal it is.

🎯 Goal: Learn why polymorphism is needed by creating a base class and derived classes, then using a pointer to call the correct sound function for each animal type.

📋 What You'll Learn

Create a base class called Animal with a virtual function makeSound().

Create two derived classes called Dog and Cat that override makeSound().

Create a pointer of type Animal* and assign it to objects of Dog and Cat.

Call makeSound() using the Animal* pointer and observe the output.

💡 Why This Matters

🌍 Real World

Polymorphism is used in software to handle different objects through a common interface, like managing different shapes in a drawing app or different payment methods in an online store.

💼 Career

Understanding polymorphism is essential for C++ developers to write clean, maintainable, and extensible code in real-world applications.

1

Create the base class Animal

Write a class called Animal with a public virtual function makeSound() that prints "Animal sound".

C++

// Your code here

Need a hint?

Use virtual keyword before the function to allow overriding.

2

Create derived classes Dog and Cat

Create classes called Dog and Cat that inherit from Animal. Override makeSound() in Dog to print "Woof" and in Cat to print "Meow".

C++

// Your code here

Need a hint?

Use override keyword to indicate you are overriding the base class function.

3

Use Animal pointer to call makeSound

Create an Animal* pointer called animalPtr. Assign it to a Dog object and call makeSound(). Then assign it to a Cat object and call makeSound().

C++

// Your code here

Need a hint?

Use pointer syntax animalPtr->makeSound() to call the function.

4

Print the output to see polymorphism in action

Add cout statements to print the sounds produced by animalPtr->makeSound() calls. Run the program to see the output.

C++

// Your code here

Need a hint?

The output should show Woof and Meow on separate lines.