Object Oriented Programming in C++

What is Object-Oriented Programming (OOPs) in C++?

In C++, object-oriented programming (OOP) is a paradigm that models real-world entities using classes and objects, allowing code to be reused and modularized. Encapsulation, inheritance, and polymorphism are key aspects that will enable developers to construct versatile and maintainable software.

Basic OOP concepts in C++

The concept of OOPs in the C++ programming language is based on 8 key pillars, which are:

1. Class
2. Object
3. Inheritance
4. Polymorphism
5. Abstraction
6. Encapsulation
7. Dynamic Binding
8. Message Passing

Class

A class is a collection of objects that have similar attributes. A template or blueprint is used to generate items. A logical entity cannot be physical. The term "Class" indicates to the compiler that we are creating a class definition.

Objects

An object is defined as an item with state and behavior, such as a chair, bike, marker, pen, table, car, etc. It can be physical or conceptual, both tangible and unimportant.

Creating Objects in C++

In C++ object-oriented programming, objects are created by first declaring a class as a blueprint and then instantiating objects from that class. This step assigns memory to the object and initializes its member variables, allowing interaction with its methods and properties.

Inheritance

Inheritance is a process by which one object inherits all of the characteristics and behaviors of its parent object. You can develop new classes that are based on existing ones. Inheriting from an existing class allows you to reuse its methods and fields. You can now reuse members of the parent class. Therefore, there is no need to define the member again. 

Types of Inheritance

The five types of inheritance that C++ provides are as follows:

1. Single inheritance
   
2. Multiple inheritance
3. Multilevel inheritance
4. Hierarchical inheritance
5. Hybrid inheritance

Polymorphism

Polymorphism is a concept that allows us to do a single action in multiple ways. Polymorphism can be accomplished through method overloading and overriding.​ 

Types of Polymorphism

There are two types of polymorphism:

1. Compile-time Polymorphism
2. Runtime Polymorphism

Abstraction

Abstraction is the process of hiding implementation details and simply displaying functionality to the user. For example, when sending an SMS, only vital information is displayed, while internal details are hidden. We employ abstract classes and interfaces for abstraction.

Encapsulation

Encapsulation helps to combine functions and data into a single unit. It is possible to achieve this by privatizing the scope of data members. This feature renders the program inaccessible to the outside world.

Dynamic Binding

In dynamic binding, the code that will be executed in response to the function call is determined at runtime. To accomplish this, C++ includes a feature called virtual functions.

Message Passing

Objects communicate by exchanging information. Message passing entails specifying the name of the object, the name of the function, and the data to be transmitted.

Advantages of OOP in C++

• The OOP allows for code reuse and extends the use of existing classes.
• Due to the existence of objects and classes, object-oriented programming facilitates code maintenance. There is no reason to rearrange the code.
• This feature of the C++ programming language is also useful in data-hiding approaches. It is particularly useful in preventing data and information from leaking.
• Object-oriented programming allows you to imitate real-world occurrences more effectively.

Disadvantages of OOP in C++

• OOP programs take longer to run due to their size, resulting in slower execution.
• OOP is not a universal language, hence it can only be used in certain situations. It is only used when needed. It is not appropriate for a wide range of issues.
• Everything in OOP is represented as an object, thus we must first understand objects.