Difference Between Inheritance and Polymorphism

What is Polymorphism?

The word Polymorphism means having many forms. Polymorphism is considered one of the essential elements of Object-Oriented Programming. It lets the object determine which form of the function to implement at compile and at run-time.

There are two types of Polymorphism-

1. Compile-time Polymorphism (Method Overloading): This type is achieved by function or operator overloading.
    
2. Runtime Polymorphism (Method Overriding): This type of Polymorphism is achieved by Function Overriding. 

Key Points About Polymorphism

Here are key points about polymorphism in object-oriented programming:

• Definition: Polymorphism allows objects of different classes to be treated as objects of a common superclass.
   
• Types: Includes compile-time (static) polymorphism (method overloading) and runtime (dynamic) polymorphism (method overriding).
   
• Method Overloading: Enables a class to have multiple methods with the same name but different parameters.
   
• Method Overriding: Subclasses can provide a specific implementation of a method that is already defined in its superclass.
   
• Dynamic Binding: The actual method implementation called is determined at runtime based on the object type.
   
• IS-A Relationship: Utilizes inheritance to achieve polymorphic behavior.
   
• Interface Implementation: Interfaces in languages like Java allow for polymorphic behavior through method signatures.
   
• Flexibility and Extensibility: Promotes flexibility in designing systems and allows for easy extension by adding new classes.
   
• Enhances Code Readability: Enables more readable and understandable code through common interfaces and method names.

Example of Polymorphism 

Let us understand further with some examples:

• C++

C++

#include <iostream>
using namespace std;
class A {
    int a, b, c;
    
public:

    void add() {
        cout << "Enter two numbers: ";
        cin >> a >> b;
        cout << "Sum: " << (a + b) << endl;
    }
    
    void add_three() {
        cout << "Enter three numbers: ";
        cin >> a >> b >> c;
        cout << "Sum: " << (a + b + c) << endl;
    }
    
    virtual void print() {
        cout << "Class A" << endl;
    }
};

class B : public A {

public:
    void print() {
        cout << "Class B" << endl;
    }
};

int main() {
    A a1;
    B b1;

    a1.add();
      a1.add_three();

    b1.print();
    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

Output

Enter two numbers: 5 6
Sum: 11
Enter three numbers: 2 3 4
Sum: 9
Class B

Benefits of Polymorphism 

• The codes can be reused with the help of Polymorphism.
   
• It saves a lot of time since classes are written, tested and implemented at once. 
   
• Polymorphism offers flexibility to programmers to write programs. It uses one method for multiple executions as needed. 
   
• Polymorphism supports singular variable names for multiple data types.
   
• Coupling between various functionalities is reduced using Polymorphism.

Difference Between Inheritance and Polymorphism

We will now explore the difference between inheritance and Polymorphism.
 

Frequently Asked Questions

What are OOPs?

Object-Oriented Programming(OOPs) is a form of the journey of programming that is based on objects instead of just functions and procedures. Singular objects are grouped into classes. OOPs allow clarity in programming, thereby allowing simplicity in solving complex problems.

What is the difference between a class and a structure?

A Class is a user-defined blueprint from which objects are formed. It consists of a set of instructions that are to be completed on the objects. In comparison, a structure is a  user-defined pack of variables which are of a distinct data type.

What are the advantages of Polymorphism?

By using polymorphism, code flexibility is achieved as various operations by using methods with identical names according to the needs can be performed. The main advantage of using polymorphism is implementation to an abstract base class or an interface can be utilised.

What is the difference between inheritance and abstraction?

Inheritance establishes relationships where one class derives behaviors and properties from another, while abstraction focuses on defining a blueprint with relevant details hidden for implementation. Inheritance deals with "is-a" relationships, whereas abstraction focuses on "what it does" without implementation details.

Conclusion

In this article, we discussed about the difference between Inheritance and Polymorphism. We started with the introduction, understanding the key points, and benefits, and later looked at the difference table between them.  If you wish to know more about Polymorphism, do check out Virtual Functions & Runtime Polymorphism in C++ and Inheritance in Java .

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