When looking up programming languages, you may encounter the term “object-oriented.” Python is an object-oriented language; so is Java, Python, C++, C#, PHP, and several others.
But, what is object-oriented programming? That’s a great question, and one that is asked by many beginner programmers.
Once you know how object-oriented programming works, you’ll be able to spot connections between different object-oriented programming languages that will deepen your understanding.
In this guide, we break down the basics of programming languages and how object-oriented programming works, and explore the main features of object-oriented programming.
What is a Programming Language?
A programming language is a set of rules and procedures that allow programmers to give computers a set of instructions to execute. Every programming language has its own syntax, which, once learned, allows you to tell a computer what tasks it should perform.
Think about it this way. English is a language that allows you to communicate with English speakers. When you know the basic rules of English, you can talk with anyone else who understands those same rules. But, computers cannot understand English, or any other “traditional” language for that matter.
We use programming languages to communicate with computers. These languages allow you to write specific instructions that a computer can read. Then, once these instructions are written, the computer will execute them. In programming, we refer to these instructions as “code,” or “computer programs.”
What is Object-Oriented Programming?
In object-oriented programming (OOP), programmers define the data type of a data structure, and the functions that can be applied to that data structure.
In object-oriented programming languages, the structure of data in an application is stored in a class. You can think of a class as a blueprint for a structure of data. Objects are used to create individual items of that class.
Object-oriented programming is a type of programming paradigm, which is a term used to refer to the different styles programming languages can use.
How Does Object-Oriented Programming Work?
Object-oriented programming languages use classes and objects to represent data.
Classes are a blueprint for an object.
Consider an application that stores data on bank accounts. Classes act as blueprints for what data the application can store. They can state that a bank account stores a customer’s name, an account number, their balance, and other information.
Objects, on the other hand, are individual instances of a class.
By themselves, classes only create a blueprint. If you want to use that blueprint, you need to create an object of that class. For instance, an object of a bank account class may store the name and account number for an individual customer like John Appleseed or Bertie Paulson.
What Are the Main Features of Object-Oriented Programming?
Classes and objects are at the core of all object-oriented programming, hence the term “object-oriented.”
There are three main features of object-oriented programming with which you should be familiar. These are:
While these words are long—and sound a little intimidating—there is no need to worry. Let’s discuss what each means.
What is Inheritance?
Inheritance allows you to create a new class using details from an existing class.
Inheritance is so important because it allows you to reduce repetition in your code.
Suppose you are developing an application for a bank. The application should allow the bank to store information on savings accounts and checking accounts.
Considering these two account types are very similar—they both store money and will need to track things like an account holder’s name and the day the account was opened—it would be counterproductive to create two classes from scratch to store information.
That’s where inheritance comes in. We can inherit the properties of a checking account from the savings account class. That way, we don’t need to define a new class from scratch to store information about our checking accounts; we can use some of the structure we used to define a savings account.
What is Encapsulation?
Encapsulation refers to bundling data, alongside the methods that operate on that data, into a single unit in a program.
In object-oriented programming, classes allow you to encapsulate the data in a structure. In a class, you can create a template that outlines both the data that can be stored in objects of the class as well as the functions or methods that can be run on that data.
So, suppose we are developing an application for a bank that uses two classes.
One class may store the structure for a savings account. This may include the fact that a savings account should have a balance, account holder’s name, and a certain interest rate. Another class may store the structure for a child’s bank account. This may track the fact that a child’s account should have a balance, account holder’s name, and be restricted.
Each of these classes are separate in our code, and without inheritance, each of these classes cannot access data or functions from each other.
What is Abstraction?
When you’re building an application, you may notice that your codebase will get substantially larger over time. In object-oriented programming, this means you may end up with a large number of different objects and classes that you need to track.
To make managing a larger application more efficient, abstraction was added as a core feature of object-oriented programming.
Abstraction means each object in a program should only expose the relevant data about an object. This helps reduce the complexity of an object, and increase efficiency.
One way to think about abstraction is to consider how you use your computer. Using a computer is relatively simple. There’s a desktop, a keyboard, and a mouse that you use to interact with the computer.
But, computers are actually very complex, powered by a wide range of different programs coming together. Computer manufacturers know that not everyone wants to learn how to code to use a computer, so they “abstracted” away some of the complexity to make it easier to use a computer.
This is similar to how abstraction works in programming. Instead of tracking every change in every class, each class only shows the relevant data about that class.
What Are the Advantages of Object-Oriented Programming?
Object-oriented programming is only one of many different structures used by programming languages. What makes object-oriented programming so special?
Let’s discuss a few of the benefits object-oriented structures provide to programming languages.
Object-oriented programming languages allow you to break down an application into objects and classes. This is beneficial because it gives your application a more modular structure, which makes it easier to maintain a codebase as it grows larger.
Inheritance allows you to reuse code in your application, thereby reducing repetition. If you want to define a data structure for three different types of data that store similar values, you can use inheritance to do so efficiently and effectively.
Because inheritance allows you to reuse code, if you need to make a change to a wide number of similar classes, you can do so by changing the main class instead of making manual changes to each individual class in a program.
#3: Problem Solving
When you’re trying to solve a problem in code, you should break it down into smaller components and analyze each individually. Because object-oriented languages already break down programs into objects and classes, it is typically easier to solve problems in your code.
What Languages Use the Object-Oriented Paradigm?
Languages like C, FORTRAN, and BASIC, on the other hand, do not use classes and objects, and so are not object-oriented programming languages.
The Bottom Line
If you’re new to coding, you may feel somewhat intimidated by the concept of object-oriented programming.
But don’t worry—as you start coding, you’ll become more familiar with how objects and classes work. In fact, the best way to learn about object-oriented programming is to practice.
This article should give you an idea of how object-oriented programming applies to a specific language that you know (or want to learn). For example, if you’re learning Python, you may want to research how object-oriented principles like classes, objects, and inheritance are applied to the language.
Object-oriented programming is a well-established development practice, present in many of the world’s most popular programming languages today. Now that you know how it works, you are in a better position to continue on your journey to learn coding.