The main intent of introducing the C++ programming language was to add object-oriented features to the C language. OOPs offer several benefits or advantages to the designer and user, and there are various areas where OOPs play an essential role, including user interface design, simulation, modeling, etc. This article on OOPs in C++ will help you understand and learn all about C++ object-oriented programming.
What Are OOPS Concepts In C++?
OOPs, Object Oriented Programming C++ is an approach or a programming pattern where the programs are structured around objects rather than functions and logic. It makes the data partitioned into two memory areas, i.e., data and functions, and helps make the code flexible and modular.
Object-oriented programming mainly focuses on objects that are required to be manipulated. In OOPs, it can represent data as objects that have attributes and functions.
Why Do You Need Object-Oriented Programming?
The earlier approaches to programming were not that good, and there were several limitations as well. Like in procedural-oriented programming, you cannot reuse the code again in the program, and there was the problem of global data access, and the approach couldn’t solve real-world problems very well.
In object-oriented programming, it is easy to maintain the code with the help of classes and objects. Using inheritance, there is code reusability, i.e., you don’t have to write the same code again and again, which increases the simplicity of the program. Concepts like encapsulation and abstraction provide data hiding as well. Now have a look at some basic concepts of OOPS in C++.
Basic Object-Oriented Programming (OOPS) Concept in C++
There are some basic concepts that act as the building blocks of OOPs.
- Classes & Objects
So now, you will understand each of these concepts in detail.
An Object can be defined as an entity that has a state and behavior, or in other words, anything that exists physically in the world is called an object. It can represent a dog, a person, a table, etc. An object means a combination of data and programs, which further represent an entity. The benefits of classes and objects include:
1. Encapsulation: Classes allow encapsulating data and related functions into a single unit, providing data hiding and preventing direct access. Objects represent instances of classes, enabling modular and organized code structure.
2. Reusability: Classes facilitate code reusability by allowing the creation of multiple objects with the same structure and behavior. This promotes efficient development and maintenance of applications.
3. Modularity: Classes provide a modular approach to programming by grouping related data and functions together. This enhances code organization, readability, and understandability.
Class can be defined as a blueprint of the object. It is basically a collection of objects which act as building blocks.
A class contains data members (variables) and member functions. These member functions are used to manipulate the data members inside the class.
Abstraction helps in the data-hiding process. It helps in displaying the essential features without showing the details or the functionality to the user. It avoids unnecessary information or irrelevant details and shows only that specific part that the user wants to see. The benefits of Abstraction includes:
1. Simplified Interface: Abstraction allows hiding complex implementation details and exposing a simplified interface to the user. This promotes ease of use and reduces complexity, as users can interact with high-level abstractions without needing to understand the underlying complexities.
2. Code Maintenance: By focusing on essential features and hiding unnecessary implementation details, abstraction improves code maintainability. Changes made to the underlying implementation are isolated, reducing the impact on other parts of the codebase.
3. Flexibility: Abstraction enables the creation of generalized interfaces, which can be implemented differently for various use cases. This provides flexibility and allows developers to adapt and extend the functionality of the code without affecting the code using abstraction.
The wrapping up of data and functions together in a single unit is known as encapsulation. It can be achieved by making the data members' scope private and the member function’s scope public to access these data members. Encapsulation makes the data non-accessible to the outside world. The benfits of encapsulation include:
1. Data Protection: Encapsulation hides the internal implementation details of an object, protecting the data from unauthorized access or modification. It provides data integrity and maintains the consistency of the object's state.
2. Code Organization: Encapsulation helps organize code by grouping related data and functions together within a class. This improves code readability and maintainability by providing a clear structure and reducing code clutter.
3. Code Reusability: Encapsulation facilitates code reusability by encapsulating functionality within objects. Objects can be easily reused in different parts of the code or in different projects, promoting efficient development and reducing redundant code.
Inheritance is the process in which two classes have an is-a relationship among each other and objects of one class acquire properties and features of the other class. The class which inherits the features is known as the child class, and the class whose features it inherited is called the parent class. For example, Class Vehicle is the parent class, and Class Bus, Car, and Bike are child classes. The benefits of Inheritance include:
1. Code Reusability: Inheritance allows classes to inherit properties and behavior from a base class, promoting code reuse. Derived classes can extend and specialize the functionality of the base class, eliminating the need to rewrite common code.
2. Polymorphism: Inheritance enables polymorphism, where objects of derived classes can be treated as objects of their base class. This allows for more flexible and dynamic programming, as different derived classes can be used interchangeably through a common interface.
3. Hierarchical Organization: Inheritance establishes a hierarchical relationship among classes, reflecting real-world or conceptual hierarchies. This improves code organization, understandability, and maintainability by representing relationships and dependencies in a structured manner.
Let’s have a look at an example of inheritance.
As we can see, there are two classes named parent and child. In line 12, the child class inherits the parent class. Initially, you created an instance of the child class, through which you are calling name1 and name2 variables; both of these string variables are holding Harley and Davidson, respectively.
Since child class is inheriting parent class, when you call using the object of the child class, you get the result name1 as Harley and name2 as Davidson.
Below is the output.
Polymorphism means many forms. It is the ability to take more than one form. It is a feature that provides a function or an operator with more than one definition. It can be implemented using function overloading, operator overload, function overriding, and virtual functions. The benfits include:
1. Code Flexibility: Polymorphism allows different objects to be treated uniformly through a common interface. This promotes code flexibility, as functions or algorithms can work with objects of different types without needing to know their specific implementations.
2. Code Extensibility: Polymorphism enables the addition of new derived classes that adhere to the same interface without modifying existing code. This extensibility simplifies code maintenance and allows for easy integration of new features.
3. Code Readability: Polymorphism enhances code readability by expressing intent and behavior through the use of abstract interfaces. It allows for more concise and expressive code, as the focus is on what needs to be done rather than how it is done.
Let’s have a look at an example where we are implementing function overriding.
As you can see in the above example, there are three classes. Class Animal is the parent class, Class Cheetah, which is the derived class, and Class Dolphin is again the derived class of Animal class.
All three classes have a function of the same name, i.e., speed, but the definition of this speed function is different in all three classes. Inside the main function, firstly, you are invoking the speed function using the object of the parent class, then using the object of child class Cheetah, you are again invoking the function, and similarly, you are invoking the function using the object of dolphin class.
Below is the output of the above program. You can see that when you call the function using the object of the parent class, it invokes the function of the parent class. But when you call the function using the object of the child class, it overrides the parent class function and prints the function of the child class.
Now go through the advantages of C++ OOPs.
Advantages of OOPs
There are various advantages of object-oriented programming.
- OOPs provide reusability to the code and extend the use of existing classes.
- In OOPs, it is easy to maintain code as there are classes and objects, which helps in making it easy to maintain rather than restructuring.
- It also helps in data hiding, keeping the data and information safe from leaking or getting exposed.
- Object-oriented programming is easy to implement.
After reading this tutorial on OOPS in C++, you would have understood why you need Object-oriented programming, what C++ OOPs are, and the basic concepts of OOPs like polymorphism, inheritance encapsulation, etc. You also learned about the advantages of C++ OOPs, along with examples of polymorphism and inheritance.
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Do you have any questions regarding this tutorial on OOPS concepts in C++? If you do, then please put them in the comments section. We’ll help you solve your queries. To learn more about C++ OOPs, click on the following link: C++ OOPs. Happy learning!