Master the 4 Pillars of Object-Oriented Programming: A Comprehensive Guide to Next-Level Coding 💻🔨

Master the 4 Pillars of Object-Oriented Programming: A Comprehensive Guide to Next-Level Coding 💻🔨

Unleashing the Power of Object-Oriented Programming: Mastering the 4 Essential Pillars for Next-Level Programming! 💻

Unlock the power of encapsulation, abstraction, inheritance, and polymorphism to write efficient and scalable code with Object-oriented Programming. 🔨📚

Image by author via Dalle 2


A popular interview question concerns the four core concepts in object oriented programming. These concepts are:

  • encapsulation
  • abstraction
  • inheritance
  • and polymorphism.

Let’s look at each of these concepts. 🙌

Before object-oriented programming, we had procedural programming, which divided a program into a set of functions. So, we had data sorted into a bunch of variables and functions that operate on the data. This style of programming is very simple and straightforward and often it’s what you will learn as part of your first programming subject at a University. But as your programs grow, you will end up with a bunch of functions that are all over the place. 😦

Photo by Sigmund on Unsplash


You might find yourself copying and pasting lines of code over and over. You make a change to one function, and then several other functions break and that’s what we call spaghetti code because there is so much interdependency between all these functions that it becomes problematic. Object-oriented programming came to solve this problem because here we combine a group of related variables and functions into a unit, and we call that unit an object. We refer to these variables as properties and the functions as methods.


Here is an example❗️

Think of a car. A car is an object with properties such as make, model, and color, and methods like start, stop, and move.

Photo by Campbell on Unsplash

Le me give you a real programming example now.

Think of the local storage object in your browser. Every browser has a local storage object that allows you to store data locally. This local storage object has a property like length, which returns the number of objects in the storage, and methods like set item and remove item. So, in object-oriented programming, we group related variables and functions that operate on them into objects. And this is what we call encapsulation.

As Uncle Bob says (Robert C. Martin), the best functions are those with no parameters. The fewer the number of parameters, the easier it is to use and maintain that function. So that’s encapsulation.

Now, let’s look at abstraction.

Think of a DVD player as an object. This DVD player has a complex logic board on the inside and a few buttons on the outside that you interact with. You simply press the play button, and you don’t care what happens on the inside because all that complexity is hidden from you. This is abstraction in practice.

Photo by Brett Jordan on Unsplash


We can use the same technique in our objects, so we can hide some of the properties and methods from the outside, and this gives us a couple of benefits. ✅ The first benefit is that we’ll make the interface of those objects simpler.

Using and understanding an object with a few properties and methods is easier than an object with several properties and methods.


The second benefit is that it helps us reduce the impact of change.

Let’s imagine that tomorrow we change these inner or private methods. None of these changes will leak to the outside because we don’t have any code that touches these methods outside of their containing object. We may delete a method or change its parameters, but none of these changes will impact the rest of the application’s code. So with abstraction, we reduce the impact of change! ✊

Now, the third core concept in object-oriented programming is inheritance, the mechanism that allows you to eliminate redundant code.

Here’s an example❗️

Think of HTML elements like text boxes, drop-down lists, checkboxes, and so on. All these elements have a few things in common: they should have properties like hidden, an inner HTML, and methods like click and focus. Instead of redefining all these properties and methods for every type of HTML element, we can define them once in a generic object, call it HTML element, and have other objects inherit these properties and methods. So inheritance helps us eliminate redundant code. 🐔


And finally, let’s talk about polymorphism.

“Poly” means many, “morph” means form.

So polymorphism means “many forms”. ✅


In object-oriented programming, polymorphism is a technique that allows you to get rid of long if-else or switch-case statements.

Let’s go back to our HTML elements example where all these objects should have the ability to be rendered on a page, but the way each element is rendered is different from the others. With object orientation, we can implement a render method in each of these objects and the render method will behave differently depending on the type of the object we are referencing. So, we can get rid of the nasty switch-case statements and use just one line of code.

So, here are the benefits of object-oriented programming: using encapsulation, we can group related variables and functions together and this way, we can reduce complexity. Now, we can reuse these objects in different parts of a program or in different programs. ✔️


With abstraction, we can hide the details and the complexity and show only the essentials. This technique reduces complexity and also isolates the impact of changes in the code. ✔️

With inheritance, we can eliminate redundant code, and with polymorphism, we can refactor ugly switch-case statements. ✔️


Thank you for reading! 👊

Object-Oriented Programming: A Comprehensive Guide to Next-Level Coding








All images are provided by the author via Unsplash & Dalle 2 ✅

Programming | code | polymorphism | variable functions | redundant code | object properties