Introduction
Object-oriented programming (OOP) is a computer programming model that organizes software design around data or objects rather than functions and logic. An object can be defined as a data field that has unique properties and behavior.
OOP focuses on the objects that developers want to manipulate rather than the logic required to manipulate them. This approach is suitable for programming software that is large, complex, and actively updated or maintained. This includes applications for manufacturing and design as well as mobile applications. For example, OOP can be used to produce system simulation software.
The organization of an object-oriented program also makes this method useful for collaborative development, where projects are divided into groups. Additional benefits of OOP include code reusability, scalability, and efficiency.
The first step in OOP is to gather all the objects a programmer wants to manipulate and identify how they relate to each other – a practice known as data modeling.
Examples of an object can range from physical entities, such as a human being described by attributes such as name and address, to small computer programs, such as widgets.
When an object is recognized, it is tagged with a class of objects that defines the type of data it contains and any logical sequences that can manipulate it. Each distinct logical sequence is known as a method. Objects can communicate with well-defined interfaces called messages.
What is the structure of object-oriented programming?
The structure or building blocks of object-oriented programming include the following:
- Classes are user-defined data types that serve as a blueprint for individual objects, properties, and methods.
- Objects are instances of a class that are created with specifically defined data. Objects can correspond to real-world objects or an abstract entity. When a class is initially defined, the description is the only object that is defined.
- Methods are functions that objects can perform. They are defined inside a class that describe the behaviors of an object. Each method in a class definition begins with a reference to an instance object. Additionally, subroutines within an object are called instance methods. Programmers use methods to provide reusability or to maintain functionality within an object at a time.
- Attributes represent the state of an object. In other words, they are characteristics that distinguish classes. Objects have data stored in the attributes section. Class attributes belong to the class itself and are defined in the class template.
What are the main principles of OOP?
- Encapsulation. The principle of encapsulation states that all important information is contained within an object and only selected information is exposed. The implementation and state of each object are kept private in a defined class. Other objects do not have access to this class or the authority to make changes. They can only call a list of public functions or methods. This data hiding feature increases the security of the application and prevents unwanted data corruption.
- Abstraction. Objects only expose internal mechanisms that are relevant for use by other objects and hide any unnecessary implementation code. A derived class can extend its functionality. This concept can help developers make further changes or additions over time more easily.
- Inheritance. Classes can reuse code and features from other classes. Relationships and subclasses between objects can be assigned, enabling developers to reuse common logic while still maintaining a unique hierarchy. Inheritance makes data analysis seamless, reducing development time and ensuring a higher level of accuracy.
- Polymorphism. Objects are designed to share behaviors and can take more than one form. The program determines which meaning or usage is necessary for each implementation of that object from a parent class, reducing the need for duplicate code. A child class is then created that extends the functionality of the parent class. Polymorphism enables different types of objects to pass through an interface.
- Syntax. This is the set of rules that define how words and punctuation are organized in a programming language.
- Coupling. This is the degree to which software elements are connected to each other. For example, if one class changes its properties, every other class changes as well.
- Association. This is a relationship between one or more classes. Associations can be one-to-one, many-to-many, one-to-many, or many-to-one.
What are examples of object-oriented programming languages?
While Simula is considered the first object-oriented programming language, many other programming languages are used with OOP today. But some programming languages pair better with OOP than others. For example, programming languages that are considered pure OOP languages treat everything as an object. Other programming languages are designed primarily for OOP, but include some procedural processing. Some of the most popular programming languages are designed for or with OOP in mind.
For example, popular pure OOP languages include:
- Ruby
- Scala
- JADE
- Emerald
Programming languages primarily designed for OOP include:
- Java
- Python
- C++
Other programming languages that pair with OOP include:
- Visual Basic .NET.
- PHP
- JavaScript
What are the benefits of OOP?
The benefits of OOP include:
- Modularity. Encapsulation enables objects to be self-contained, making debugging and collaborative development easier.
- Code reusability can be reused through inheritance, meaning a team doesn't have to write the same code multiple times.
- Productivity. Programmers can quickly build new applications using multiple libraries and reusable code.
- It is easily expandable and scalable. Programmers can implement system functions independently.
- Security. Using encapsulation and abstraction, complex code is hidden, software maintenance is made easier, and Internet protocols are protected.
- Flexibility. Polymorphism enables a function to adapt to the class it is placed in. Different objects can also pass through an interface.
- Code maintenance: Parts of a system can be updated and maintained without the need to make major adjustments.
- Lower cost. Other benefits, such as maintainability and reusability, reduce development costs.
Criticism of OOP
Developers have criticized the object-oriented programming model for a number of reasons. The biggest concern is that OOP places too much emphasis on the data component of software development and not enough focus on computations or algorithms. Additionally, OOP code can be more complex to write and take longer to compile.
Other common criticisms include the fact that inheritance comes with drawbacks such as brittle base classes. Additionally, objects are sometimes clearer when isolated, but harder to understand when working in a real application.
Alternative OOP methods include:
- Functional programming This includes languages like Erlang and Scala, which are used for telecommunications and fault-tolerant systems.
- Structured or modular programming. This includes languages like PHP and C#.
- Imperative Programming This alternative to OOP focuses on functionality rather than models. Imperative programming languages include C++ and Java.
- Declarative programming This programming style includes statements about what the desired task or result is, but not how to achieve it. Declarative programming languages include Prolog and Lisp.
- Logic programming, which is based more on formal logic and uses languages such as Prolog, involves a set of statements that express facts or rules about a problem domain. It focuses on tasks that can benefit from rule-based logical queries.
Result
Most advanced programming languages allow developers to combine models because they can be used for different programming methods. For example, JavaScript and Scala can be used for OOP and functional programming.
