What Is Object-Oriented Programming (OOP)?

Object-oriented programming (OOP) is a programming paradigm based on the concept of objects. In it, objects can contain data called “fields,” “attributes,” or “properties.” They can perform actions called “procedures” or “methods” implemented in code. OOP allows users to design computer programs by making them out of objects that interact with one another. It is also called “object-oriented design (OOD).”

You can compare OOP to real-world objects and how they interact. In this scenario, classes represent blueprints for objects and their attributes. Methods, meanwhile, are models for real-world properties and behaviors. Think of it this way: A car can be an object with attributes like color, model and methods like drive and brake. In this context, OOP helps in modeling complex systems and makes code easy to reuse and maintain.

Want to learn more than the OOP meaning? Read on! 

Read More about OOP

If you are a computer programmer who wants to learn more about OOP, then you are in the right place. Know the OOP meaning, its main principles, examples, benefits, and more here.

A Brief History of OOP

You can learn most about anything by looking at its origins. Here is a summary of OOP’s history.

• Late 1950s–early 1960s: The idea of “objects” in programming was born among the artificial intelligence (AI) group at the Massachusetts Institute of Technology (MIT).

• 1961–1967: Simula was developed in Norway, which introduced essential object-oriented ideas like classes, inheritance, and dynamic binding. It is generally accepted as the first language with the primary features and framework of an object-oriented language.

• 1968: AED-0, MIT’s version of the ALGOL programming language, connected data structures (plexes) and procedures, became the predecessors of what were later termed “messages,” “methods,” and “member functions.” Topics like data abstraction and modular programming were also discussed.

• 1970s: The first version of the Smalltalk programming language was developed at Xerox PARC by Alan Kay, Dan Ingalls, and Adele Goldberg.

• 1979: The Flavors object-oriented Lisp was developed, which introduced multiple inheritance and mixins.

• 1981: Byte Magazine highlighted Smalltalk and OOP, introducing the ideas to a wide audience.

• 1982: A paper about LOOPS, the object system for Interlisp-D, which was influenced by Smalltalk and Flavors, was published.

• Mid-1980s: New object-oriented languages like Objective-C, C++, and Eiffel emerged.

• 1990s: OOP became the primary programming means, especially as more languages supported it.

Today, new languages like Python and Ruby have emerged that combine object-oriented and procedural styles. The most commercially important “pure” object-oriented languages continue to be Java, C#, and Visual Basic.NET (VB.NET).

What Are the Key Concepts of OOP?

We listed the key principles behind or concepts of OOP below.

Class

A class is the fundamental unit of C++ that paved the way for OOP. It is a user-defined data type that users can access and use by creating an instance of it. It has its own data members and member functions. Think of it as an object’s blueprint. Both member functions and data members are found in classes. The data members inside the class are manipulated using member functions.

Object

When you create a class, its description is the first object you define. An instance of a class exists in an object. Note that a system does not allocate any memory space when you specify a class but it is allocated when it is instantiated, such as when an object is formed.

Syntax

Syntax refers to the principles that specify how a language is structured. In programming languages, it is a set of rules that define and guide how words, punctuation, and symbols are organized in a programming language. Without it, it would be hard to comprehend the semantics or meaning of a language. More specifically, a compiler or interpreter will not be able to understand the code if it does not follow the syntax of a language.

Encapsulation

Encapsulation is the process of grouping functions and data into a single entity. To access data members, the member function’s scope must be set to “public” while the data members’ scope must be set to “private.” Based on this theory, an item contains all important information but only a small subset of it is available to the outside world. Each object has a private class that contains its implementation and state.

Polymorphism

Multiple classes can use the same method name via polymorphism, which also involves redefining methods for derived classes. Apart from having several forms, objects can have shared behaviors. To avoid writing duplicate code, the software determines which usage or meaning is required each time an object from a parent class is used.

Inheritance

Broadly speaking, inheritance is the process of gaining properties. As such, an object in OOP can inherit the properties of another. That way, developers can reuse common functionality while retaining a distinct hierarchy by assigning relationships and subclasses between items. This speeds up development and provides greater accuracy by requiring a more in-depth data investigation. A parent-child relationship, for instance, is symbolized via inheritance.

Abstraction

This concept applies to Java. It is the act of representing key features without including supporting information. It is a means to develop a brand-new data type appropriate for a particular application. It avoids providing extraneous or pointless facts and only displays the precise portion users requested. It is crucial since it prevents you from performing the same task more than once.

Coupling

Coupling describes the degree to which one software element is connected to another. Note that these elements can be a class, package, component, subsystem, or system. It denotes the level of familiarity one object or class has with another. So, if one class changes attributes, the dependent changes in the other will also change. The magnitude of interdependence between two classes will determine how changes occur.

Cohesion

A class’s cohesion is determined by how closely and meaningfully coupled to one another its methods and properties are, along with how intently they focus on carrying out a single, clearly defined goal for the system. It is a measure of how narrowly focused a class’s responsibilities are. Because their methods and properties do not relate to one another logically, low cohesive classes are hard to maintain.

Association

An association is a relationship between two distinct classes established with the aid of their objects. One-to-one, one-to-many, many-to-one, and many-to-many associations are all possible.

Aggregation

In aggregation, each object has a distinct life cycle. Ownership, though, prevents the child object from being a part of another parent object. Java aggregation depicts the link between an object that contains other objects and is a weak association. It illustrates the connection between a component and a whole, where a part can exist without a whole. A unique type of semantically weak link called an “aggregation” occurs when unrelated things are combined.

Composition

Composition is an association that depicts a relationship between a part and a whole, where a part cannot exist without a whole. Aggregation can take various forms, including composition. Since child objects lack a life cycle, they all automatically disappear when the parent object does. One object cannot exist without the other in any composition between two entities. As a result, both entities depend on one another.

Modularity

Modular design refers to the division of a system into many functional pieces known as “modules” that can be combined to create a more extensive application. Modularity and encapsulation are inextricably related. When mapping encapsulated abstractions into actual, physical modules, high cohesion within the modules and limited intermodule interaction or coupling can be seen as the definition of modularity.

Constructors and Methods

A constructor is a specific kind of subroutine called to create an object. It sets up the new object for use and frequently accepts arguments from the constructor to set up necessary member variables. A method, meanwhile, is a procedure connected to a message and an object. An object’s state data and behavior make up its interface, which describes how any of its numerous consumers may use it. A method is a consumer-parameterized object activity.

What Are Examples of OOP Languages?

OOP languages can be classified in various ways. Some are considered pure. Others were designed primarily for OOP. And still others, pair well with OOP. The tables below sums things up.

What Are the Benefits of OOP?

OOP provides several benefits. We named them below.

• It makes troubleshooting and collaborative development possible due to its modularity.
• Code developed using OOP is reusable through inheritance, which means developers do not have to write the same code multiple times.
• It enhances productivity in that programmers can construct new programs quickly using multiple libraries and reusable code.
• OOP enables easy upgrades and scalability since programmers can implement system functionalities independently.
• Interface descriptions in OOP, such as descriptions of external systems, are simple because of the message-passing techniques used for object communication.
• OOP is secure due to encapsulation and abstraction, which hides complex code. This feature also makes software maintenance easier while protecting Internet protocols.
• Its polymorphism, which enables a single function to adapt to the class it is placed in, makes it flexible. In addition, different objects can also pass through the same interface.
• Since parts of a system can be updated and maintained without making significant adjustments, OOP makes code maintenance a breeze.
• Due to its other benefits like easy maintenance and reusability, OOP reduces development costs.

Does OOP Have Downsides?

Developers have criticized OOP for various reasons. Their largest concern? It overemphasizes the data component of software development and does not focus enough on computation or algorithms. In addition, OOP code may be more complicated to write and take longer to compile.

Other common criticisms include the fact that inheritance comes with drawbacks like fragile base classes. Also, objects are sometimes clearer while isolated but are harder to understand when they operate in actual programs.

What Are Potential Alternatives to OOP?

Did you know that there are alternatives to OOP? Here are some of them.

• 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 focuses on function rather than models. Its languages include C++ and Java.

• Declarative programming: This involves statements on what the task or desired outcome is but not how to achieve it. Its languages include Prolog and Lisp.

• Logical programming: This is based mostly on formal logic and uses languages like Prolog. It contains a set of sentences that express facts or rules about a problem domain. It focuses on tasks that can benefit from rule-based logical queries.

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OOP is a foundational development concept on which several high-level programming languages are built on. Its key concepts can help you understand how basic programs work, identify the root cause of bottlenecks, and resolve them through more innovative code.

Key Takeaways

• OOP allows users to design computer programs by making them out of objects that interact with one another.
• It traces its beginnings to the late 1950s.
• Its key principles include class, object, syntax, and more.
• Its languages can be considered pure, designed primarily for OOP, or pair well with OOP.
• Some of its benefits include making troubleshooting and collaborative development possible, enabling code reuse, and enhancing productivity.
• Despite its numerous benefits, it has drawbacks, too.
• Potential alternatives to it include functional, structured or modular, and imperative programming.

Sources

• https://en.wikipedia.org/wiki/Object-oriented_programming
• https://www.spiceworks.com/tech/devops/articles/object-oriented-programming/
• https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/tutorials/oop
• https://www.gartner.com/en/information-technology/glossary/oop-object-oriented-programming