O.O.P: Pleasant by Nature

How can I explain it? I’ll take you frame by frame

Object-oriented programming (OOP), is a term loosely used by young devs constantly as they start learning the basics of software development. Java, C++, C#, Python, PHP, JavaScript, Ruby and Perl, to name a few, all carry OOP qualities in their structure. The C languages, Python and Ruby are generally considered to be true OOP languages, and there remains debate in Java. In my opinion, JavaScript is the most functional of the bunch while still, supporting some OOP guidelines. The opposite of developing and adhering to the OOP paradigm would be functional or procedural programming techniques. As a young developer, it’s important to understand both concepts.

Why OOP?

In the early days of programming, all we had was procedural programming. Our applications would contain hundreds of functions one after another, listed line-by-line-by line. Constantly, developers would have to repeat themselves by calling similar functions with similar logic in multiple location so of the application. The functions would relate to each other sometimes too, further complicating what each function was try to perform as applications grew.

Procedural Programming Illustrated — a/k/a spagetti code

OOP was introduced to solve this problem. It combines like features and classes into units, or objects. Variables are referred to as properties and functions as methods.

Example: A car has properties such as a make, model and color, with methods available such as start(), stop(), and move().

The 4 Pillars of O.O.P

Encapsulation

Each object keeps its state private, inside a class. Other objects don’t have direct access to the state, can only call on it from a list of public functions (methods). Also

Example: If a cat is hungry we can feed a cat with the feed()method, but can’t directly change how hungry the cat is with decreasing the hunger property directly on the cat.

Abstraction

Extension of encapsulation. Because programs and codebases are complex and grow overtime, each object should only expose a high-level mechanism for using it.

Example: Your iPhone has a home button, which you know how to use all the time. Not critical to understand what the home button does under the hood. A software update wouldn’t change how you use the home button.

Inheritance

While large code bases grow, many objects and classes share like features. You can create a child class by deriving from another parent class, forming a hierarchy.

Example: If we need to build a program that manages a school, can create a teacher class, and then two teacher classes (regular vs. subs), while also maintaining a separate student class, which all derive their logic from “Person”.

Polymorphism

While parents and their children are different classes, they sometimes require like methods that can be used on both of the classes while still keeping them separate.

Example: A triangle, circle and rectangle are children of “Figure”, which has access to calculateSurface()and calculatePerimeter().

OOP vs. Functional Programming

Aside from procedural programming which we first looked at above, developers also have functional programming available to them separate from OOP. At the heart of functional programming, is the principle that each function should only do one particular, specific, small task for the application. It attempts to allow for very clean, readable, reliable code. Each function can be easily invoked anywhere in the application, and functions can be reused and recycle to avoid repetition of code throughout the base. In contrast, OOP uses objects to represent like features as opposed to standalone functions.

Say we wanted to create a program which would analyze the score of a basketball game.

In OOP, we would:

1. Create a Game class would would be initialized with a team and players as its children, with the players having properties of points scored, rebounds, assists, steals, etc.
2. We would create instances of the players
3. Invoke a method of pointsScored() to assign points to a player.

In a Functional Program, we would:

1. Create a players array, which is an array of a hash of their team and game played.
2. Create a pointsScored() method which returns the player name and the amount of points they scored in that game.
3. To add points to the player if they scored a basket, we could create a new method, called addPoints(), which maps through the players array and assigns the points to that player.
4. We could invoke both methods, pointScored() and addPoints() to return a new dataset: final_game.

OOP proponents would argue its paradigm does a better job making code re-useable through inheritance, and encapsulations helps managing and manipulating the dataset. Function programming developers would argue that keeping methods and datasets separated leave less room for bugs and errors. Each of the paradigms have their own use cases, but ultimately, it’s up to the dev team which structure they prefer to develop their application in.

Conclusion

Understanding the core concepts of OOP is critical for any young dev, particularly if they ever want to write in Python, Ruby or any of the C languages. While JavaScript and Java likely aren’t considered to be true OOP languages, they still maintain some OOP concepts so if you’re your FE vanilla JS dev, you shouldn’t dismiss OOP concepts. Happy coding!

How to explain object-oriented programming concepts to a 6-year-old